Papaya ringspot virus resistance in <Emphasis Type="Italic">Carica papaya</Emphasis> via introgression from <Emphasis Type="Italic">Vasconcellea quercifolia</Emphasis>     

S. V. Siar  G. A. Beligan  A. J. C. Sajise  V. N. Villegas  R. A. Drew 《Euphytica》2011,181(2):159-168

We report the first successful production of PRSV-P resistant backcross (BC) papaya plants following intergeneric hybridisation between C. papaya and a Vasconcellea species after 50 years of reports on unsuccessful attempts. This follows our previous reports of PRSV-P resistant F₁ hybrids developed by intergeneric hybridisation between C. papaya and V. quercifolia. One PRSV-P resistant BC 1 (BC₁) plant was produced after 114,839 seeds were dissected from 940 fruits. The seeds yielded 1,011 embryos and 733 germinated in vitro from which 700 developed into plantlets that were screened in a glasshouse and in the field under high disease pressure and exposure to inoculation by viruliferous aphids. From the PRSV-P resistant backcross 1 (BC₁) male plant, 1465 plants [137 BC₂, 546 SbC₂ (BC2 sib-crosses), 147 BC₃, 379 SbC₃ and 256 BC₄] were grown from seed and inoculated with PRSV-P and virus resistant BC₃ and BC₄ plants were selected from these generations. Presence or absence of virus was confirmed by ELISA serological tests. BC plants generally developed mild symptoms of PRSV-P after periods ranging from 5 to 18 months in the field but many showed the ability to produce new growth free of symptoms. All control plants developed severe symptoms after 3 months in the field. Some BC₃ and BC₄ plants were free from viral infection after 18 months in the field. Subsequently they developed very mild symptoms on their leaves and a few ringspots on their fruit. They continued to grow vigorously and produce fruit for 3 years under high disease pressure provided by the infected controls and other susceptible plants. Good quality marketable fruit were produced on these plants. Application of these results should lead to restoration of the papaya industry in virus-infested regions of the Philippines and worldwide.  相似文献   

Use of molecular markers aids in the development of diverse inbred backcross lines in Beit Alpha cucumber (<Emphasis Type="Italic">Cucumis sativus</Emphasis> L.)     

Isabelle Y. Delannay  Jack E. Staub 《Euphytica》2010,175(1):65-78

Beit Alpha cucumber (Cucumis sativus L.) is a Mediterranean fresh-market type with a relatively narrow genetic base. To broaden its base for plant improvement, 42 diverse accessions were compared employing a previously defined standard marker array to choose wide-based parental lines for use in backcross introgression. Inbred backcross lines (IBL) were developed by crossing Beit Alpha line ‘04HD5’ (De Ruiter Seeds, The Netherlands; recurrent parent) and PI 285606 (Poland; donor parent), and then selecting the most genetically diverse BC₁ and BC₂ progeny based on molecular marker profiles, followed by three generations of single-seed descent to produce 117 IBL. Molecular genotyping of IBL was then performed, and IBL were evaluated for days to anthesis, sex expression, pistillate flowers per node, lateral branch number, fruits per plant, fruit length, and fruit weight in the US, The Netherlands, Israel, and Turkey. Multivariate analyses and genetic distance comparisons indicate that IBL possessed considerable inter-line morphological and genotypic diversity. These diverse IBL will be useful in genetic studies and to evaluate Beit Alpha cross-progeny derived from IBL × elite germplasm created to broadened genetic base of this market type.  相似文献   

Inheritance of beta-carotene-associated flesh color in cucumber (<Emphasis Type="Italic">Cucumis sativus</Emphasis> L.) fruit     

H. E. Cuevas  H. Song  J. E. Staub  P. W. Simon 《Euphytica》2010,171(3):301-311

The nutritional value of cucumber (Cucumis sativus L.) can be improved by the introgression of β-carotene (i.e., provitamin A and/or orange flesh) genes from “Xishuangbanna gourd” (XIS; Cucumis sativus var. xishuangbannanesis Qi et Yuan) into US pickling cucumber. However, the genetics of β-carotene content has not been clearly defined in this US market type. Thus, three previous populations derived from a US pickling cucumber (‘Addis’) × XIS mating were evaluated for β-carotene content, from which the high β-carotene inbred line (S₄), ‘EOM 402-10’, was developed. A cross was then made between the US pickling cucumber inbred line ‘Gy7’ [gynoecious, no β-carotene, white flesh; P₁] and ‘EOM 402-10’ [monoecious, possessing β-carotene, orange flesh; P₂] to determine the inheritance of β-carotene in fruit mesocarp and endocarp tissue. Parents and derived cross-progenies (F₁, F₂, BC₁P₁, and BC₁P₂) were evaluated for β-carotene content in a greenhouse in Madison, Wisconsin. While F₁ and BC₁P₁ progeny produced mature fruits possessing white, light-green, and green (0.01–0.02 μg g⁻¹ β-carotene) mesocarp, the F₂ and BC₁P₂ progeny mesocarp segregated in various hues of white, green, yellow (0.01–0.34 μg g⁻¹ β-carotene), and orange (1.90–2.72 μg g⁻¹ β-carotene). Mesocarp and endocarp F₂ segregation adequately fit a 15:1 [low-β-carotene (0.01–0.34 μg g⁻¹): high-β-carotene (1.90–2.72 μg g⁻¹)] and 3:1 (low-β-carotene: high-β-carotene) ratio, respectively. Likewise, segregation of carotene concentration in mesocarp and endocarp tissues in BC₁P₂ progeny adequately fit a 3:1 (low-β-carotene: high-β-carotene) and 1:1 (low-β-carotene: high-β-carotene) ratio, respectively. Progeny segregations indicate that two recessive genes control the β-carotene content in the mesocarp, while one recessive gene controls β-carotene content in the endocarp. Single marker analysis of F₂ progeny using the carotenoid biosynthesis gene Phytoene synthase determined that there was no association between this gene and the observed β-carotene variation in either fruit mesocarp or endocarp.  相似文献   

Genetics of resistance to <Emphasis Type="Italic">Cucumber mosaic virus</Emphasis> in <Emphasis Type="Italic">Cucumis sativus</Emphasis> var. <Emphasis Type="Italic">hardwickii</Emphasis> R. Alef     

A. D. Munshi  Bishwajit Panda  Bikash Mandal  I. S. Bisht  E. S. Rao  Ravinder Kumar 《Euphytica》2008,164(2):501-507

The genetics of resistance to Cucumber mosaic virus (CMV) in Cucumis sativus var. hardwickii R. Alef, the wild progenitor of cultivated cucumber was assessed by challenge inoculation and by natural infection of CMV. Among the 31 genotypes of C. sativus var. hardwickii collected from 21 locations in India the lowest mean percent disease intensity (PDI) was recorded in IC-277048 (6.33%) while the highest PDI was observed in IC-331631 (75.33%). All the four cultivated varieties (DC-1, DC-2, CHC-1 and CHC-2) showed very high PDI and susceptible disease reaction. Based on mean PDI, 8 genotypes were categorized as resistant, 13 as moderately resistant, 9 as moderately susceptible and one as susceptible. A chi-square test of frequency distribution based on mean PDI in F₂ progenies of six resistant × susceptible crosses revealed monogenic recessive Mendelian ratio 1(R):3(S) to be the best fit. This monogenic recessive model was further confirmed by 1(R):1(S) ratio as the best fit for back cross with resistant parent and no fit for either 3:1 or 1:1 in the back cross with the susceptible parent. The results revealed that CMV resistance in C. sativus var. hardwickii was controlled by a single recessive gene. Considering the cross compatibility between C. sativus var. hardwickii and cultivated cucumber, the resistance trait can be easily transferred to cultivated species through simple backcross breeding.  相似文献   

Development and characterisation of a <Emphasis Type="Italic">Brassica carinata</Emphasis> inbred line incorporating genes for low glucosinolate content from <Emphasis Type="Italic">B. juncea</Emphasis>     

Angustias Márquez-Lema  José M. Fernández-Martínez  Begoña Pérez-Vich  Leonardo Velasco 《Euphytica》2008,164(2):365-375

The presence of high levels of sinigrin in the seeds represents a serious constraint for the commercial utilisation of Ethiopian mustard (Brassica carinata A. Braun) meal. The objective of this research was the introgression of genes for low glucosinolate content from B. juncea into B. carinata. BC₁F₁ seed from crosses between double zero B. juncea line Heera and B. carinata line N2-142 was produced. Simultaneous selection for B. carinata phenotype and low glucosinolate content was conducted from BC₁F₂ to BC₁F₄ plant generations. Forty-three BC₁F₄ derived lines were selected and subject to a detailed phenotypic and molecular evaluation to identify lines with low glucosinolate content and genetic proximity to B. carinata. Sixteen phenotypic traits and 80 SSR markers were used. Eight BC₁F₄ derived lines were very close to N2-142 both at the phenotypic and molecular level. Three of them, with average glucosinolate contents from 52 to 61 micromoles g⁻¹, compared to 35 micromoles g⁻¹ for Heera and 86 micromoles g⁻¹ for N2-142, were selected and evaluated in two additional environments, resulting in average glucosinolate contents from 43 to 56 micromoles g⁻¹, compared to 29 micromoles g⁻¹ for Heera and 84 micromoles g⁻¹ for N2-142. The best line (BCH-1773), with a glucosinolate profile made up of sinigrin (>95%) and a chromosome number of 2n = 34, was further evaluated in two environments (field and pots in open-air conditions). Average glucosinolate contents over the four environments included in this research were 42, 31 and 74 micromoles g⁻¹ for BCH-1773, Heera and N2-142, respectively. These are the lowest stable levels of glucosinolates reported so far in B. carinata.  相似文献   

Molecular markers assist in the development of diverse inbred backcross lines in European Long cucumber (<Emphasis Type="Italic">Cucumis sativus</Emphasis> L.)     

Isabelle Y. Delannay  Jack E. Staub 《Euphytica》2011,178(2):229-245

The popular fresh-market European Long cucumber (Cucumis sativus L.) is grown commercially worldwide under controlled, greenhouse environments. However, it has a narrow genetic base, where private and public improvement programs can trace their origins to comparatively few accessions. Therefore, a project was designed to identify diverse genotypes for use in the formation and analysis of inbred backcross (BC₂S₃) lines (IBL) to broaden the genetic base of this market class. Initially, 42 cucumber accessions were evaluated with a previously defined standard marker array to identify parents for use in backcrossing. The IBL were developed by crossing the elite commercial line NZ1 (Nunhems Vegetable Seeds, Haelen, The Netherlands) and PI 432858 (China), and then backcrossing the most genetically diverse BC₁ and BC₂ progeny to the elite parent as defined by marker analyses (19 polymorphic, mapped SSR, and SCAR marker loci), followed by three generations of single seed descent resulting in 116 IBL (BC₂S₃). The IBL were evaluated under greenhouse conditions for days to anthesis, sex expression, lateral branch number, yield, and exterior fruit quality in Madison, Wisconsin, USA (soil media), and in Haelen and Bergschenhoek, The Netherlands (soilless, hydroponic media). The IBL were genotyped using an expanded marker array (37 polymorphic SSR, SCAR, SNP, EST, BAC end, and gene-associated loci), and genetic relationships were examined by multivariate analyses using phenotypic and genotypic data. The 116 developed IBL possessed considerable morphological and genotypic diversity, where genetic distance (GD) among lines ranged between 0.00 and 0.77. These IBL possessed many commercially acceptable attributes, and, thus, genetic diversity in this market type could be substantially increased by the use of these genetically broad-based IBL during plant improvement.  相似文献   

Molecular markers linked to <Emphasis Type="Italic">Bn</Emphasis>;<Emphasis Type="Italic">rf</Emphasis>: a recessive epistatic inhibitor gene of recessive genic male sterility in <Emphasis Type="Italic">Brassica napus </Emphasis>L.     

Lu Xiao  Bin Yi  Yufeng Chen  Zhen Huang  Wei Chen  Chaozhi Ma  Jinxing Tu  Tingdong Fu 《Euphytica》2008,164(2):377-384

7–7365AB is a recessive genic male sterile (RGMS) two-type line, which can be applied in a three-line system with the interim-maintainer, 7–7365C. Fertility of this system is controlled by two duplicate dominant epistatic genes (Bn;Ms3 and Bn;Ms4) and one recessive epistatic inhibitor gene (Bn;rf). Therefore an individual with the genotype of Bn;ms3ms3ms4ms4Rf_ exhibits male sterility, whereas, plant with Bn;ms3ms3ms4ms4rfrf shows fertility because homozygosity at the Bn;rf locus (Bn;rfrf) can inhibit the expression of two recessive male sterile genes in homozygous Bn;ms3ms3ms4ms4 plant. A cross of 7–7365A (Bn;ms3ms3ms4ms4RfRf) and 7–7365C (Bn;ms3ms3ms4ms4rfrf) can generate a complete male sterile population served as a mother line with restorer in alternative strips for the multiplication of hybrid seeds. In the present study, molecular mapping of the Bn;Rf gene was performed in a BC₁ population from the cross between 7–7365A and 7–7365C. Bulked segregant analysis (BSA) and amplified fragment length polymorphism (AFLP) technique was used to identify molecular markers linked to the gene of interest. From a survey of 768 primer combinations, seven AFLP markers were identified. The closest marker, XM5, was co-segregated with the Bn;Rf locus and successfully converted into a sequence characterized amplified region (SCAR) marker, designated as XSC5. Two flanking markers, XM3 and XM2, were 0.6 cM and 2.6 cM away from the target gene, respectively. XM1 was subsequently mapped on linkage group N7 using a doubled-haploid (DH) mapping population derived from the cross Tapidor × Ningyou7, available at IMSORB, UK. To further confirm the location of the Bn;Rf gene, additional simple sequence repeat (SSR) markers in linkage group N7 from the reference maps were screened in the BC₁ population. Two SSR markers, CB10594 and BRMS018, showed polymorphisms in our mapping population. The molecular markers found in the present study will facilitate the selection of interim-maintainer.  相似文献   

Microsporogenesis of <Emphasis Type="Italic">Rps</Emphasis>8/<Emphasis Type="Italic">rps</Emphasis>8 heterozygous soybean lines     

Maria Andrea Ortega  Anne E. Dorrance 《Euphytica》2011,181(1):77-88

Phytophthora root and stem rot caused by Phytophthora sojae, is one of the most damaging diseases of soybean, for which management is principally done by planting resistant cultivars with race specific resistance which are conferred by Rps (Resistance to Phytophthora sojae) genes. The Rps8 locus, identified in the South Korean landrace PI 399073, is located in a 2.23 Mbp region on soybean chromosome 13. In eight cv. Williams (rps8/rps8) × PI 399073 (Rps8/Rps8) populations, this region exhibited strong segregation distortion. In a cross between the South Korean lines PI 399073 (Rps8/Rps8) and PI 408211B (multiple Rps genes) this region segregated in a Mendelian fashion. In this study, microsporogenesis was evaluated to identify meiotic abnormalities that may be associated with the segregation distortion of the Rps8 region. Pollen was collected from greenhouse-grown plants of the parental genotypes: Williams, PI 399073, and PI 408211B; as well as selected Rps8/rps8 RILs from Williams × PI 399073 BC₄F_2:3 and PI 399073 × PI 408211B F_4:5 populations. There were no differences for pollen viability among the genotypes. However, for PI 399073, a mix of dyads, triads, tetrads and pentads was observed. A high frequency of meiotic abnormalities including fragments, laggards, multinucleated microspores; and microcytes containing DNA was also observed in Rps8/rps8 Williams × PI 399073 BC₄F_2:3 RILs. These meiotic abnormalities may contribute to the high degree of segregation distortion present in the Williams × PI 399073 populations.  相似文献   

Inheritance of beta-carotene-associated mesocarp color and fruit maturity of melon (<Emphasis Type="Italic">Cucumis melo</Emphasis> L.)     

H. E. Cuevas  J. E. Staub  P. W. Simon 《Euphytica》2010,173(1):129-140

Melon (Cucumis melo L.) fruit production in U.S. can be improved through the introgression of early fruit maturity (FM) and the enhancement of fruit color [i.e., quantity of β-carotene (QβC); orange mesocarp]. However, the genetics of FM and QβC have not been clearly defined in U.S. Western Shipping market class melons (USWS). Thus, a cross was made between the monoecious, early FM Chinese line ‘Q 3-2-2’ (non-carotene accumulating, white mesocarp) and the andromonecious, comparatively late FM USWS line ‘Top Mark’ (carotene accumulating; orange mesocarp) to determine the inheritance of FM and QβC in melon. Parents and derived cross-progenies (F₁, F₂, F₃, BC₁P₁, and BC₁P₂) were evaluated for FM and QβC at Hancock, Wisconsin over 2 years. Estimates of narrow-sense heritability (h _N²) for QβC and FM as defined by F₁, F₂, and BC (by individuals) were 0.55 and 0.62, respectively, while estimates based on F₃ families were 0.68 and 0.57, respectively for these traits. Mesocarp color segregation (F₂ and BC₁P₂) fit a two gene recessive epistatic model, which in turn, interacts with other minor genes. Although the inheritance of QβC and FM is complex, introgression (e.g., by backcrossing) of early FM genes resident in Chinese germplasm into USWS market types is possible. Such introgression may lead to increased yield potential in USWS market types while retaining relatively high β-carotene fruit content (i.e., orange mesocarp), if stringent, multiple location and early generation family selection (F_3–4) is practiced for FM with concomitant selection for QβC.  相似文献   

Stay-green expression in early generation sorghum [<Emphasis Type="Italic">Sorghum bicolor</Emphasis> (L.) Moench] QTL introgression lines     

B. Kassahun  F. R. Bidinger  C. T. Hash  M. S. Kuruvinashetti 《Euphytica》2010,172(3):351-362

Reduced leaf senescence (stay-green) has been demonstrated to improve tolerance of post-flowering moisture stress in grain sorghum. A number of quantitative trait loci (QTLs) associated with stay-green have been identified in sorghum, to facilitate transfer of this trait into adapted genetic backgrounds. This study reports initial evaluations, in both well watered and post-flowering stress environments, following partial introgression (BC₂F₃/BC₁F₄ generations) of four stable stay-green QTLs (StgB, Stg1, Stg3 and Stg4) from donor parent B35 to senescent variety R 16. The majority of the introgression lines had higher leaf chlorophyll levels at flowering (a distinctive trait of the donor parent) and a greater percentage green leaf area during the latter part of grain filling, than did R 16, indicating that the stay-green QTLs were expressed phenotypically in the R 16 background. None of the QTL introgression lines achieved the same level of stay-green as B35, however. Maintenance of a greater relative green leaf area during the latter half of grain filling was related to a greater relative grain yield in two of three post-flowering moisture deficit environments in which the materials were evaluated (r ² = 0.34 in 2004–2005 and r ² = 0.76 in 2005–2006), as was a direct measure of leaf chlorophyll in one of the post-flowering stress environments in which this was measured (r ² = 0.42, P < 0.05). Thus the study provided useful evidence that the marker-assisted backcross transfer of stay-green QTLs from B35 into an adapted, but senescent background has the potential to enhance tolerance of post-flowering drought stress in sorghum.  相似文献   

Morphological,cytological and reproductive characterization of tri-species hybrids (GOS) between <Emphasis Type="Italic">Pennisetum glaucum</Emphasis>, <Emphasis Type="Italic">P. orientale</Emphasis> and <Emphasis Type="Italic">P. squamulatum</Emphasis>     

P. Kaushal  Aarti Khare  S. A. Siddiqui  A. Agrawal  Sharmishtha Paul  D. R. Malaviya  A. K. Roy  S. N. Zadoo 《Euphytica》2010,174(2):261-281

New tri-species hybrids (GOS) in the genus Pennisetum involving the cultivated species pearl millet (P. glaucum L.) and two wild species, viz. P. squamulatum Fresen and P. orientale L. C. Rich, are reported. Six hybrid plants were recovered after crossing a backcross hybrid (2n = 3x = 23, GGO) between P. glaucum (2n = 2x = 14, GG) and P. orientale (2n = 2x = 18, OO) with F₁s (2n = 6x = 42, GGSSSS) between P. glaucum (2n = 4x = 28, GGGG) and P. squamulatum (2n = 8x = 56, SSSSSSSS). The hybrids were perennial, morphologically intermediate to their parents, and represented characters from the three contributing species. The hybrids contained 2n = 44 chromosomes (GGGSSO) representing 21, 14 and nine chromosomes from P. glaucum, P. squamulatum and P. orientale, respectively. Meiotic and flow-cytometric analysis suggested origin of these hybrids from unreduced female and reduced male gametes. Average chromosome configuration (8.42_I + 14.32_II + 1.62_III + 0.52_IV) at Meiosis showed limited inter-genomic pairing indicating absence of significant homology between the three genomes. The hybrids were male sterile (except one) and highly aposporous. P. orientale was identified to induce apospory in hybrid background with P. glaucum at diploid and above levels, though it was quantitatively affected by genomic doses from sexual parent. A case of inducible and recurrent apospory is presented whereby a transition from Polygonum-type sexual embryo-sacs to Panicum-type aposporous embryo-sacs was observed in diploid interspecific hybrids. Results supported independent origin and partitioning of the three apomixis-components (apomeiosis, parthenogenesis, and functional endosperm development), reported for the first time in Pennisetum. Potential utilization of GOS hybrids in understanding genome interactions involved in complex traits, such as perenniality and apomixis, is discussed.  相似文献   

Genetic analysis reveals a dominant <Emphasis Type="Italic">S</Emphasis> locus and an <Emphasis Type="Italic">S</Emphasis> suppressor locus in natural self-compatible <Emphasis Type="Italic">Brassica napus</Emphasis>     

Chaozhi Ma  Chunyan Li  Yongqiang Tan  Wei Tang  Jianfeng Zhang  Changbin Gao  Tingdong Fu 《Euphytica》2009,166(1):123-129

A self-incompatible (SI) line, S-1300, and its maintainer 97-wen135, a self-compatible (SC) line, were used to study the inheritance of maintenance for self-incompatibility in B. napus. The ratio of SI plants to SC plants from S-1300 × 97-wen135 F₂ and (S-1300 × 97-wen135) × 97-wen135 was 346:260 and 249:232, fitting the expected ratio of 9:7 and 1:1, respectively. Based on these observations, here we propose a genetic model in which two independent loci, S locus and S suppressor locus (sp), are predicted to control the inheritance of maintenance for self-incompatibility in B. napus. The genotypes of S-1300 and 97-wen135 are S ₁₃₀₀ S ₁₃₀₀ sp ₁₃₀₀ sp ₁₃₀₀ and S ₁₃₅ S ₁₃₅ sp ₁₃₅ sp ₁₃₅ , respectively. S ₁₃₅ is dominant to S ₁₃₀₀ , but coexistence of sp ₁₃₀₀ and sp ₁₃₅ fails to suppress S locus. Both S ₁₃₀₀ and S ₁₃₅ can be suppressed by sp ₁₃₅ , while sp ₁₃₀₀ can suppress S ₁₃₅ but not S ₁₃₀₀ . The model contains two characteristics: that a dominant S locus exists in self-compatible B. napus, and that co-suppression will occur when sp loci are heterozygous. The model has been validated by the segregation of S phenotypes in the (S-1300 × 97-wen135) × S-1300, the progenies of SC S-1300 × 97-wen135 F₂ plants and DH population developed from S-1300 × 97-wen135 F₁. This is the first study to report co-suppression of S suppressor loci in B. napus. The genetic model will be very useful for developing molecular markers linked to maintenance for self-incompatibility and for dissecting the mechanism of SI/SC in B. napus.  相似文献   

Identification and genetics of resistance to cercospora leaf spot (<Emphasis Type="Italic">Cercospora zonata</Emphasis>) in faba bean (<Emphasis Type="Italic">Vicia faba</Emphasis>)     

R. B. E. Kimber  J. G. Paull 《Euphytica》2011,177(3):419-429

The fungal disease cercospora leaf spot CLS (Cercospora zonata) has affected major faba bean (Vicia faba) production regions in southern Australian in the last several years. This study offers the first report of sources of resistance to CLS in faba bean and describes techniques to evaluate resistance to C. zonata in faba bean genotypes within a controlled environment. The method was rapid (43 days), repeatable (R ² > 0.74) and demonstrated positive correlations (R ² > 0.45–0.80) to data collected from field disease nurseries under naturally established CLS epiphytotics. All faba bean cultivars currently adopted by the Australian industry were found to be susceptible to CLS and defoliation was found to be an important component of disease expression. Genetic analysis of segregation patterns in F ₂ derived F ₃ families of 1322/2*Farah (resistant*susceptible) showed the mode of inheritance of resistance to C. zonata was monogenic dominant. F ₃ families were shown to segregate in the ratio of 1:2:1 for homozygous resistant: heterozygous: homozygous susceptible (χ₂² = 2.78; P > 0.05) and individual plants within heterozygous F ₃ families segregated in the ratio of 3:1 for resistant: susceptible responses (χ₁² = 2.93; P > 0.05). Monogenic dominant inheritance also explained the change in frequency of resistant and susceptible plants within a population of cv. Cairo following one generation of self-pollination (χ² = 0.88, 0.3 < P < 0.5). The sources of resistance identified in this study are being used to transfer CLS resistance to adapted faba bean genotypes for future cultivar releases to the southern Australian industry.  相似文献   

Genetic mapping of AFLP markers in Japanese bunching onion (<Emphasis Type="Italic">Allium fistulosum</Emphasis>)     

Takayoshi?OharaEmail author  Yeon-Sang?Song  Hikaru?Tsukazaki  Tadayuki?Wako  Tsukasa?Nunome  Akio?Kojima 《Euphytica》2005,144(3):255-263

Summary The first genetic linkage map of Japanese bunching onion (Allium fistulosum) based primarily on AFLP markers was constructed using reciprocally backcrossed progenies. They were 120 plants each of (P₁)BC₁ and (P₂)BC₁ populations derived from a cross between single plants of two inbred lines: D1s-15s-22 (P₁) and J1s-14s-20 (P₂). Based on the (P₂)BC₁ population, a linkage map of P₁ was constructed. It comprises 164 markers – 149 amplified fragment length polymorphisms (AFLPs), 2 cleaved amplified polymorphic sequences (CAPSs), and 12 simple sequence repeats (SSRs) from Japanese bunching onion, and 1 SSR from bulb onion (A. cepa) – on 15 linkage groups covering 947 centiMorgans (cM). The linkage map of P₂ was constructed with the (P₁)BC₁ population and composed of 120 loci – 105 AFLPs, 1 CAPS, and 13 SSRs developed from Japanese bunching onion and 1 SSR from bulb onion – on 14 linkage groups covering 775 cM. Both maps were not saturated but were considered to cover the majority of the genome. Nine linkage groups in P₂ map were connected with their counterparts in P₁ map using co-dominant anchor markers, 13 SSRs and 1 CAPS.  相似文献   

Broadening the genetic base of <Emphasis Type="Italic">Brassica napus</Emphasis> canola by interspecific crosses with different variants of <Emphasis Type="Italic">B. oleracea</Emphasis>     

R. Iftikhar  X. Wang  H. Rahman 《Euphytica》2018,214(8):133

Broadening the genetic base of the C genome of Brassica napus canola by use of B. oleracea is important. In this study, the prospect of developing B. napus canola lines from B. napus?×?B. oleracea var. alboglabra, botrytis, italica and capitata crosses and the effect of backcrossing the F₁’s to B. napus were investigated. The efficiency of the production of the F₁’s varied depending on the B. oleracea variant used in the cross. Fertility of the F₁ plants was low—produced, on average, about 0.7 F₂ seeds per self-pollination and similar number of BC₁ seeds on backcrossing to B. napus. The F₃ population showed greater fertility than the BC₁F₂; however, this difference diminished with the advancement of generation. The advanced generation populations, whether derived from F₂ or BC₁, showed similar fertility and produced similar size silique with similar number of seeds per silique. Progeny of all F₁’s and BC₁’s stabilized into B. napus, although B. oleracea plant was expected, especially in the progeny of F₁ (ACC) owing to elimination of the A chromosomes during meiosis. Segregation distortion for erucic acid alleles occurred in both F₂ and BC₁ resulting significantly fewer zero-erucic plants than expected; however, plants with?≤?15% erucic acid frequently yielded zero-erucic progeny. No consistent correlation between parent and progeny generation was found for seed glucosinolate content; however, selection for this trait was effective and B. napus canola lines were obtained from all crosses. Silique length showed positive correlation with seed set; the advanced generation populations, whether derived from F₂ or BC₁, were similar for these traits. SSR marker analysis showed that genetically diverse canola lines can be developed by using different variants of B. oleracea in B. napus?×?B. oleracea interspecific crosses.  相似文献   

Identification of molecular markers linked to adult plant leaf rust resistance gene <Emphasis Type="Italic">Lr48</Emphasis> in wheat and detection of <Emphasis Type="Italic">Lr48</Emphasis> in the Thatcher near-isogenic line with gene <Emphasis Type="Italic">Lr25</Emphasis>     

D. Samsampour  B. Maleki Zanjani  J. K. Pallavi  Anupam Singh  A. Charpe  S. K. Gupta  K. V. Prabhu 《Euphytica》2010,174(3):337-342

The recessive adult plant resistance (APR) gene Lr48 in wheat was tagged with flanking random amplified polymorphic DNA (RAPD) markers. Markers S336₇₇₅ in coupling and S3₄₅₀ in repulsion with Lr48 were identified in wheat line CSP44. Tests of these markers on available Thatcher near-isogenic lines (NILs) detected the likely presence of Lr48 in TcLr25. A test of allelism of APR involving the cross TcLr25 × CSP44 indicated that Lr48 was present in both lines. A separate experiment on inheritance of resistance in an F₂ population of TcLr25 × Agra Local confirmed the presence of a dominant seedling resistance gene (Lr25) and a recessive APR gene (Lr48) in TcLr25. This study demonstrated the value of molecular markers in identifying the presence of masked genes in genetic stocks where direct phenotyping failed to detect their presence.  相似文献   

Superior CMS (<Emphasis Type="Italic">Ogura</Emphasis>) lines with better combining ability improve yield and maturity in cauliflower (<Emphasis Type="Italic">Brassica oleracea</Emphasis> var. <Emphasis Type="Italic">botrytis</Emphasis>)     

S. S. Dey  S. R. Sharma  R. Bhatia  Chander Parkash  R. N. Barwal 《Euphytica》2011,182(2):187-197

Three CMS lines, Ogu1A, Ogu2A and Ogu3A were selected among ten lines after BC₇ based on superior commercial, floral and seed setting traits. Introgression of sterile Ogura cytoplasm in cauliflower nuclear background reduced the flower size but did not affect commercial and seed setting traits drastically. Line × Tester analysis was done by taking these three CMS lines free from floral deformities as female parent with nine diverse lines of snowball cauliflower as tester. The parent Ogu2A exhibited highest GCA effect for curd yield (4.51) and harvest index (1.97) while Ogu1A exhibited highest GCA for earliness (−2.73). The parent, Ogu2A exhibited significant GCA for curd length (0.39) while, none of the CMS lines showed significant GCA for curd diameter and depth. Heterosis for curd yield was highest in the hybrid, Ogu2A × Kt-22 (63.5%) followed by Ogu1A × WF (36.9%) and Ogu1A × Kt-15 was the best hybrid for earliness followed by Ogu3A × Kt-22 with heterosis of −14.4% and −11.7%. However, the number of heterotic hybrids for yield and earliness was low indicating narrow genetic base of the snowball cauliflower.  相似文献   

Genetic analysis of resistance to <Emphasis Type="Italic">Fusarium</Emphasis> root rot in common bean     

Clare Mukankusi  John Derera  Rob Melis  Paul T. Gibson  Robin Buruchara 《Euphytica》2011,182(1):11-23

Fusarium root rot (FRR) is a major disease of common bean worldwide. Knowledge of the inheritance of resistance to FRR would be important in devising strategies to breed resistant varieties. Therefore, a 12 × 12 full diallel mating scheme with reciprocal crosses was performed to generate 132 F₁ progenies, which were then advanced to the F₃. The progenies were evaluated for resistance to FRR under green house conditions in Uganda. General combining ability (GCA) effects were highly significant (P ≤ 0.01) for disease scores. Specific combining ability effects were not significant (P > 0.05) in the F₁, but were highly significant (P < 0.01) in the F₃ generation. These results indicate that resistance to FRR was governed by genes with additive effects in combination with genes with non-additive effects. Reciprocal differences were also significant (P = 0.01) at F₁ and F₃, primarily reflecting a large influence of maternal effects in both these generations. In fact, susceptible parents did not differ significantly (P > 0.05) for disease scores when used as paternal parents in the F₃, but differed strongly as maternal parents (P = 0.0002). Generally, the progenies were distinctly more resistant when the resistant parent was used as the female in crosses, especially as observed in the F₃. The maternal effects were strong in the F₃ generation, suggesting a complex form of cytoplasmic–genetic interaction. The non-maternal reciprocal effects in the F₃ were significant (P < 0.05) in both the resistant × resistant diallel, and in the resistant × susceptible crosses. Mid-parent heterosis (MPH) occurred in most crosses, with average heterosis approximately equal in each of the three generations, indicating that epistasis was probably more influential than dominance of individual genes. Gene-number formulas indicated that several genes were involved in resistant × susceptible crosses. Among resistant × resistant crosses, many produced continuous distributions of F₁ progeny scores, suggesting polygenic inheritance, while bi-modal distributions were characteristic of the F₃ distributions, and fit expected ratios for two or three loci segregating in each cross. Dominant forms of epistasis favoring resistance were strongly indicated. Parent–offspring heritability estimates were moderate. Overall, the results indicate that resistant parents contain a number of different resistance genes that can be combined with the expectation of producing strong and durable resistance. The lines MLB-49-89A, MLB-48-89, RWR719 and Vuninkingi, with large and negative GCA effects, contributed high levels of resistance in crosses and would be recommended for use in breeding programs.  相似文献   

Creation of new maize germplasm using alien introgression from <Emphasis Type="Italic">Zea mays</Emphasis> ssp. <Emphasis Type="Italic">mexicana</Emphasis>     

Lingzhi Wang  Aifang Yang  Chunmei He  Mingli Qu  Juren Zhang 《Euphytica》2008,164(3):789-801

Zea mays ssp. mexicana, an annual wild relative of maize, has many desirable characteristics for maize improvement. To transfer alien genetic germplasm into maize background, F₁ hybrids were generated by using Z. mays ssp. mexicana as the female parent and cultivated maize inbred line Ye515 as the male parent. Alien introgression lines, with a large range of genetic diversity, were produced by backcross and successive self-pollinations. A number of alien introgression lines with the predominant traits of cultivated maize were selected. Genomic in situ hybridization (GISH) proved that small chromosome segments of Z. mays ssp. mexicana had been integrated into the maize genome. Some outstanding alien introgression lines were evaluated in performance trials which showed 54.6% hybrids had grain yield greater than that of hybrid check Yedan12 which possessed 50% Ye515 parentage, and 17.1, 9.9% hybrids had grain yield competitive or greater than those of Nongda108 and Zheng958, which were elite commercial hybrids in China, respectively. The results indicated that some of the introgression lines had excellent agronomic traits and combining ability for maize cultivar, and demonstrated that Z. mays ssp. mexicana was a valuable source for maize breeding, and could be used to broaden and enrich the maize germplasm.  相似文献   

A new male sterile mutant LZ in wheat (<Emphasis Type="Italic">Triticum aestivum</Emphasis> L.)     

Kuanji Zhou  Shihong Wang  Yuqin Feng  Wanquan Ji  Genxuan Wang 《Euphytica》2008,159(3):403-410

Genetic male sterility (GMS) genes in wheat (Triticum aestivum L.) can be used for commercial hybrid seed production. A new wheat GMS mutant, LZ, was successfully used in the 4E-ms system for producing hybrid wheat, a new approach of producing hybrid seed based on GMS. Our objective was to analyse the genetic mechanism of male sterility and locate the GMS gene in mutant LZ to a chromosome. We firstly crossed male sterile line 257A (2n = 42) derived from mutant LZ to Chinese Spring and several other cultivars for determining the self-fertility of the F₁ hybrids and the segregation ratios of male-sterile and fertile plants in the F₂ and BC₁ generations. Secondly, we conducted nullisomic analysis by crossing male sterile plants of line 257A to 21 self-fertile nullisomic lines as male to test the F₁ fertilities and to locate the GMS gene in mutant LZ to a chromosome. Thirdly, we conducted an allelism test with Cornerstone, which has ms1c located on chromosome 4BS. All F₁s were male fertile and the segregation ratio of male-sterile: fertile plants in all BC₁ and F₂ populations fitted 1:1 and 1:3 ratios, respectively. The male sterility was stably inherited, and was not affected by environmental factors in two different locations or by the cytoplasm of wheat cultivars in four reciprocal cross combinations. The results of nullisomic analysis indicated the gene was on chromosome 4B. The allelism test showed that the mutant LZ was allelic to ms1c. We concluded that the mutant LZ has common wheat cytoplasm and carries a stably inherited monogenic recessive gene named ms1g.  相似文献