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1.
We have previously reported that expression of salt-responsive genes, including Bruguiera gymnorhiza ankyrin repeat protein 1 (BgARP1), enhances salt tolerance in both Agrobacterium tumefaciens and Arabidopsis. In this report, we further characterized BgARP1-expressing Arabidopsis to elucidate the role of BgARP1 in salt tolerance. BgARP1-expressing plants exhibited more vigorous growth than wild-type plants on MS plates containing 125–175 mM NaCl. Real-time PCR analysis showed enhanced induction of osmotin34 in the 2-week-old transformants under 125 mM NaCl. It was also showed that induction of typical salt-responsive genes, including RD29A, RD29B, and RD22, was blunted and delayed in the 4-week-old transformants during 24 h after 200 mM NaCl treatment. Ion content analysis showed that transgenic plants contained more K+, Ca2+, and NO3 −, and less NH4 +, than wild-type plants grown in 200 mM NaCl. Our results suggest that BgARP1-expressing plants may reduce salt stress by up-regulating osmotin34 gene expression and maintaining K+ homeostasis and regulating Ca2+ content. These results indicate that BgARP1 is functional on a heterogeneous background.  相似文献   

2.
Agrobacterium-mediated genetic transformation was performed using embryonic axes explants of pigeon pea. Both legume pod borer resistant gene (cry1Ac) and plant selectable marker neomycine phosphor transferase (nptII) genes under the constitutive expression of the cauliflower mosaic virus 35S promoter (CaMV35S) assembled in pPZP211 binary vector were used for the experiments. An optimum average of 44.61% successfully hardened dot blot Southern hybridization positive plants were obtained on co-cultivation media supplemented with 200 μM acetosyringone without L-cysteine. The increased transformation efficiency from a baseline of 11.53% without acetosyringone to 44.61% with acetosyringone was further declined with the addition of different concentrations of L-cysteine to co-cultivation media. Transgenic shoots were selected on 50 and 75 mg L−1 kanamycin. Rooting efficiency was 100% on half-strength Murashige and Skoog medium with 20 g L−1 sucrose and 0.5 mg L−1 indole butyric acid in the absence of kanamycin. Furthermore, 100% seed setting was found among all the transgenic events. The plants obtained were subjected to multi- and nochoice tests to determine the behavioral responses and mortality through Helicoverpa armigera bioassays on the leaf and relate their relationship with the expression of cry1Ac protein which was found to be less in leaf as compared to the floral buds, anther, pod, and seed.  相似文献   

3.
A phytase gene (phyA), isolated from Aspergillus ficuum (AF537344), was introduced into cotton (Gossypium hirsutum L.) by Agrobacterium-mediated transformation to increase the phosphorus (P) acquisition efficiency of cotton. Southern and Northern blot analyses showed that the phyA was successfully incorporated into the cotton genome and expressed in transgenic lines. After growing for 45 days with phytate (Po) as the only P source, the shoot and root dry weights of the transgenic plants all increased by nearly 2.0-fold relative to those of wild-type plants, but were similar to those of transgenic plants supplied with inorganic phosphorus. The phytase activities of root extracts prepared from transgenic plants were 2.4- to 3.6-fold higher than those from wild-type plants, and the extracellular phytase activities of transgenic plants were also 4.2- to 6.3-fold higher. Furthermore, the expressed phytase was secreted into the rhizospheres as demonstrated by enzyme activity staining. The transgenic plants accumulated much higher contents of total P (up to 2.1-fold after 30 days of growth) than the wild-type plants when supplied with Po. These findings clearly showed that cotton plant transformed with a fungal phytase gene was able to secret the enzyme from the root, which markedly improved the plant’s ability to utilize P from phytate. This may serve as a promising step toward the development of new cotton cultivars with improved phosphorus acquisition.  相似文献   

4.
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   

5.
The inheritance of the resistance to Fusarium oxysporum f. sp. melonis (F.o.m.) races 0 and 2 in ‘Tortuga’, a Spanish cantalupensis accession, was studied from crosses of ‘Tortuga’ by the susceptible line ‘Piel de Sapo’ and the resistant one ‘Charentais-Fom1’ that carries the resistance gene Fom-1. The segregation patterns observed in the F2 (‘Tortuga’ × ‘Piel de Sapo’) and the backcross (‘Piel de Sapo’ × (‘Tortuga’ × ‘Piel de Sapo’) populations, suggest that resistance of ‘Tortuga’ to races 0 and 2 of F.o.m. is conferred by two independent genes: one dominant and the other recessive. In the F2 derived from the cross between accessions ‘Tortuga’ and ‘Charentais-Fom1’, the lack of susceptible plants indicated that the two accessions are carrying the same resistance gene (Fom-1). The analysis of 158 F2 plants (‘Tortuga’ × ‘Piel de Sapo’) with a Cleaved Amplified Polymorphic Sequence marker 618-CAPS, tightly linked to Fom-1 (0.9 cM), confirmed that ‘Tortuga’ also carries a recessive gene, that we propose to symbolize by fom-4.  相似文献   

6.
A triploid hybrid with an ABC genome constitution, produced from an interspecific cross between Brassica napus (AACC genome) and B. nigra (BB genome), was used as source material for chromosome doubling. Two approaches were undertaken for the production of hexaploids: firstly, by self-pollination and open-pollination of the triploid hybrid; and secondly, by application of colchicine to axillary meristems of triploid plants. Sixteen seeds were harvested from triploid plants and two seedlings were confirmed to be hexaploids with 54 chromosomes. Pollen viability increased from 13% in triploids to a maximum of 49% in hexaploids. Petal length increased from 1.3 cm (triploid) to 1.9 cm and 1.8 cm in the two hexaploids and longest stamen length increased from 0.9 cm (triploid) to 1.1 cm in the hexaploids. Pollen grains were longer in hexaploids (43.7 and 46.3 μm) compared to the triploid (25.4 μm). A few aneuploid offsprings were also observed, with chromosome number ranging from 34 to 48. This study shows that trigenomic hexaploids can be produced in Brassica through interspecific hybridisation of B. napus and B. nigra followed by colchicine treatment.  相似文献   

7.
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 (8.42I + 14.32II + 1.62III + 0.52IV) 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   

8.
The genus Kalanchoe is currently divided into section Kalanchoe and section Bryophyllum, and there has been no successful report on the production of inter-sectional hybrids. Therefore, reciprocal crosses were made between Kalanchoe spathulata (sect. Kalanchoe) and K. laxiflora (sect. Bryophyllum) in order to obtain basic information on the reproductive barriers between these two sections. The seeds were aseptically germinated in vitro and the plants were grown in greenhouse till flowering. When K. spathulata was used as a maternal donor, 39 out of 80 plants showed intermediate characteristics between K. spathulata and K. laxiflora. In contrast, no plants were obtained in the reverse crosses. Hybridity of these plants was confirmed by flow cytometric analysis, chromosome numbers and RAPD analysis. Bulbil formation on the leaf margin as one of the conspicuous characteristics of K. laxiflora was not observed in the hybrids. Some of the hybrid lines showed some pollen fertility, but failed to yield viable seeds by self-pollination or backcross-pollination. Successful production of the inter-sectional hybrid between the two species suggests that they are not so distantly related as considered previously.  相似文献   

9.
Pearl millet (Pennisetum glaucum) is the most important cereal in crop-livestock production systems in arid and drier semi-arid environments valued for its grain and dry stover. The conventional approach of improving grain yield through greater partitioning of biomass to the grain and decreased stover yield is not a viable strategy for arid regions where biomass also needs to be improved. The current research tested the hypothesis whether biomass can be improved without extending the crop duration. The 232 F5 lines derived from a cross (J28 × RIB 335/18) were evaluated in their testcross form along with three commercial hybrids under arid zone conditions. Biomass, grain and stover yields, panicle number, grain size and grain number panicle−1 varied 1.8 to 2.7 fold in progeny testcrosses. Variation in duration of flowering time accounted for only 2% of variation in biomass, indicating that considerable scope existed for selection of testcrosses, and by implication, of F5 progenies with high biomass independent of crop duration. Stover yield accounted for 72% of differences in total biomass with remaining accounted for by grain yield. From among 92 and 132 testcrosses that had flowering time comparable to two early checks, most had significantly higher biomass, grain and stover yields than these early checks but none of the testcrosses had earliness on par with extra-early maturing hybrid HHB 67. Mean superiority of best 5% testcrosses over early checks was 58% for biomass, 68% for stover yield and 53% for grain yield. The results indicated that there are good prospects of improving biomass in arid zone pearl millet without significantly compromising crop duration.  相似文献   

10.
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   

11.
Agrobacterium tumefaciens mediated in planta transformation protocol was developed for castor, Ricinus communis. Two-day-old seedlings were infected with Agrobacterium strain EHA105/pBinBt8 harboring cry1AcF and established in the greenhouse. Screening the T1 generation seedlings on 300 mg L−1 kanamycin identified the putative transformants. Molecular and expression analysis confirmed the transgenic nature and identified high-expressing plants. Western blot analysis confirmed the co-integration of the nptII gene in the selected transgenic plants. Bioassay against Spodoptera litura corroborated with high expression and identified five promising effective lines. Analysis of the T2 generation plants proved the stability of the transgene indicating the feasibility of the method.  相似文献   

12.
Nicotiana wuttkei Clarkson and Symon discovered in the 1990s in Australia may be of potential interest to breeders as it carries resistance to Peronospora hyoscyami de Bary. The crossability between N. wuttkei (2n = 4x = 32) and three N. tabacum (2n = 4x = 48) cultivars (‘Puławski 66’, ‘Wiślica’ and ‘TN 90’) and the morphology and cytology of their amphihaploid hybrids (2n = 4x = 40) were studied. Seeds were produced only when N. wuttkei was used as the maternal parent, but under normal germination all seedlings died. Viable F1 hybrids of N. wuttkei × N. tabacum cv. ‘Puławski’ and N. wuttkei × N. tabacum cv. ‘Wiślica’ were obtained only by in vitro cotyledon culture. The amphihaploid plants were intermediate between the parents for most morphological traits. In 46.4% of the PMC’s, only univalents were present. The remainder of the cells had 1–5 bivalents and 1–2 trivalents. In spite of a detectable frequency of monads (2.6%), dyads (2.6%) and triads (4.5%), the hybrids were self and cross sterile.  相似文献   

13.
Asian rust, caused by the fungus Phakopsora pachyrhizi, is the most severe disease currently threatening soybean crops in Brazil. The development of resistant cultivars is a top priority. Genetic characterization of resistance genes is important for estimating the improvement when these genes are introduced into soybean plants and for planning breeding strategies against this disease. Here, we infected an F2 population of 140 plants derived from a cross between ‘An-76’, a line carrying two resistance genes (Rpp2 and Rpp4), and ‘Kinoshita’, a cultivar carrying Rpp5, with a Brazilian rust population. We scored six characters of rust resistance (lesion color [LC], frequency of lesions having uredinia [%LU], number of uredinia per lesion [NoU], frequency of open uredinia [%OU], sporulation level [SL], and incubation period [IP]) to identify the genetic contributions of the three genes to these characters. Furthermore, we selected genotypes carrying these three loci in homozygosis by marker-assisted selection and evaluated their genetic effect in comparison with their ancestors, An-76, PI230970, PI459025, Kinoshita and BRS184. All three genes contributed to the phenotypes of these characters in F2 population and when pyramided, they significantly contributed to increase the resistance in comparison to their ancestors. Rpp2, previously reported as being defeated by the same rust population, showed a large contribution to resistance, and its resistance allele seemed to be recessive. Rpp5 had the largest contribution among the three genes, especially to SL and NoU. Only Rpp5 showed a significant contribution to LC. No QTLs for IP were detected in the regions of the three genes. We consider that these genes could contribute differently to resistance to soybean rust, and that genetic background plays an important role in Rpp2 activity. All three loci together worked additively to increase resistance when they were pyramided in a single genotype indicating that the pyramiding strategy is one good breeding strategy to increase soybean rust resistance.  相似文献   

14.
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   

15.
The oilseed Brassica rapa flowers and matures earlier than B. oleracea, as well as their amphidiploid B. napus. Therefore, earliness of B. rapa has been investigated as a source of variation for earliness in B. napus breeding programs. Variation for days to flower exists in B. oleracea; however, its earliest flowering variant B. alboglabra flowers 2–3 weeks later than B. napus. We hypothesized that the C genome of B. alboglabra carries alleles for early flowering which are different from the C-genome alleles of B. napus; and these alleles can be used for the improvement of B. napus. To test this, we examined flowering time in pedigree and DH populations from two B. napus × B. alboglabra crosses. A B. napus line with about a week earlier flowering than the B. napus parent was achieved through reconstitution of its C genome following pedigree selection. Introgression of the B. alboglabra allele in the early flowering pedigree lines is also evident from the presence of B. alboglabra-specific SSR alleles in this line. However, application of doubled haploidy failed to generate any line that flowered earlier than the B. napus parent, which is probably due to the difficulty of obtaining large numbers of euploid B. napus DH lines from this interspecific cross. Thus, we demonstrate that a trait of the diploid species, which apparently looks undesirable, might in fact be highly valuable for the improvement of amphidiploids; and knowledge from this research can also be applied for other traits.  相似文献   

16.
In a previously made cross Brassica napus cv. Oro (2n = 38) × Capsella bursa-pastoris (2n = 4x = 32), one F1 hybrid with 2n = 38 was totally male sterile. The hybrid contained no complete chromosomes from C. bursa-pastoris, but some specific AFLP (amplified fragment length polymorphism) bands of C. bursa-pastoris were detected. The hybrid was morphologically quite similar to ‘Oro’ except for smaller flowers with rudimentary stamens but normal pistils, and showed good seed-set after pollination by ‘Oro’ and other B. napus cultivars. The fertility segregation ratios (3:1, 1:1) in its progenies indicated that the male sterility was controlled by a single recessive gene. In the pollen mother cells of the male sterile hybrid, chromosome pairing and segregation were normal. Histological sectioning of its anthers showed that the tapetum was multiple layers and was hypertrophic from the stage of sporogenic cells, and that the tetrads were compressed by the vacuolated and disaggregated tapetum and no mature pollen grains were formed in anther sacs, thus resulting in male sterility. The possible mechanisms for the production of the male sterile hybrid and its potential in breeding are discussed.  相似文献   

17.
Pseudomonas syringae is the main pathogen responsible for bacterial blight disease in pea and can cause yield losses of 70%. P. syringae pv. pisi is prevalent in most countries but the importance of P. syringae pv. syringae (Psy) is increasing. Several sources of resistance to Psy have been identified but genetics of the resistance is unknown. In this study the inheritance of resistance to Psy was studied in the pea recombinant inbred line population P665 × ‘Messire’. Results suggest a polygenic control of the resistance and two quantitative trait loci (QTL) associated with resistance, Psy1 and Psy2, were identified. The QTL explained individually 22.2 and 8.6% of the phenotypic variation, respectively. In addition 21 SSR markers were included in the P665 × ‘Messire’ map, of which six had not been mapped on the pea genome in previous studies.  相似文献   

18.
Interspecific hybridization was carried out between Lilium longiflorum and L. lophophorum var. linearifolium by using the cut style method of pollination, as a contrast, intraspecific hybridization between L. longiflorum ‘Gelria’ and L. longiflorum was also made, but no mature seeds and offspring were obtained from the two combinations under in vivo condition. Ovules excised from each carpel 5–35 days after pollination (DAP) were cultured on B5 or half-strength B5 medium containing sucrose at different concentrations in vitro. In L. longiflorum × L. lophophorum var. linearifolium, only 1.17% of ovules excised at 10 DAP developed into seedlings, and in L. longiflorum ‘Gelria’ × L. longiflorum, only 0.99% of ovules excised at 25 DAP developed into seedlings; none of the ovules excised at other different DAP in the two cross combinations produced any seedlings. The results showed that interspecific hybridization had a more serious post-fertilization barrier than the intraspecific hybridization, and that a lower concentration (3%) of sucrose led to better embryo development and higher percentage of seedlings in ovule cultures. All hybrid seedlings obtained were successfully transplanted to soil and grew normally. The progenies investigated were identified as true hybrids based on inter-simple sequence repeat (ISSR) analysis.  相似文献   

19.
Embryogenic callus of Phalaenopsis amabilis derived from leaf tissue was cocultivated with Agrobacterium tumefaciens strain LBA4404 harboring a plant cloning vector. The vector carried the lipid transfer protein (LTP) encoding gene cloned from cold tolerant Brazilian upland rice cv. IAPAR 9. The highest transformation efficiency (12.16%) was obtained when 1–2 mm calli were infected and cocultivated with 0.4 (OD600) A. tumefaciens for 20 min. Transgene integration of kan-resistant plants was confirmed through polymerase chain reaction analysis and Southern hybridization. Four hundred seventy transgenic plants, each derived from an independent protocorm-like body, were obtained. The expression of rice cold-inducible LTP gene in transgenic P. amabilis improved its adaptive responses to cold stress. The examination of transgenic plants revealed that enhanced cold tolerance was most likely due to the increased accumulation of several compatible solutes such as total soluble sugars, proline, antioxidant superoxide dismutase, decreased accumulation of malondialdehyde, and maintained electrolytes within the membrane compared with controls.  相似文献   

20.
In the dry regions of Chile, prolific flowering from forest plantation is particularly advantageous for honey production, in order to supplement the erratic flowering in native plants. Eucalyptus cladocalyx is a species suitable for areas with low water availability and their flowers provide a reliable source for the production of honey. The aim of this study was to examine the heritability of flowering intensity in 49 open-pollinated families of E. cladocalyx in southern Atacama Desert, Chile, with the view to the selection for prolific flowering, but with minimal impact on precocious flowering. The Bayesian variance component estimation model was assumed using the Gibbs sampling algorithm. Threshold models were fitted to flowering data (bi-character model). Flowering intensity was found to be highly heritable (posterior mean: h 2 = 0.48; and credible interval: 0.41–0.56). The posterior mean of the genetic correlation between flowering precocity and intensity was positive (r = 0.45) and according to the credible interval (0.341–0.542), it was significantly different from zero, indicating that selection on breeding values of early flowering at age three, would have significant and positive impact on flowering intensity 5 years later (or in 8-year-old trees). These results are important for the start of a small-scale breeding program for the species in southern Atacama Desert. The genetic variability found in these breeding populations may be used for breeding purposes in regions where arid environmental conditions are limiting to the establishment of eucalypts trees.  相似文献   

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