首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献，搜索用时 656 毫秒
1.
Nicotiana glauca is of potential interest to breeders as it carries resistance to black root rot of tobacco. Cytological investigations of sexual interspecific hybrids of N. tabacum T′T′TT (2n = 4x = 48) cv. ‘Wiślica’ × N. glauca GG (2n = 2x = 24) were carried out. The analyses of chromosome association at diakinesis and metaphase I in the PMCs of amphihaploid F1 T′TG (2n = 3x = 36) revealed low variable pairing with 0–5 bivalents. The sterile amphihaploids F1 were converted into partial female fertile amphidiploids T′T′TTGG by chromosome doubling. Among 36 mature plants obtained, 15 were found to have chromosome numbers (2n = 6x = 72) and were verified as amphidiploids, 9 had (2n = 6x = 70 or 71) chromosomes while the remaining 12 were haploid. True amphidiploids, in spite of quite high chromosome pairing during meiosis, were very different in pollen fertility, ranging from 0% to 85%. Male fertility disturbances did not correlate with the degree of female fertility upon pollination with N. tabacum. Sesquidiploids T′TG (2n = 5x = 60) obtained from backcrossing the amphidiploids to parental tobacco showed more than 22 bivalents, 10–12 univalents and occasional multivalents that indicated the possibility of interchange events between N. tabacum and N. glauca genomes.  相似文献   

2.
The present research aimed to study the inheritance and chromosomal location of a photoperiod‐thermo sensitive male sterility (PTSMS) gene in Xinong 291S (XN291S), which is a new PTSMS wheat line. The inheritance was studied in F1 and F2 populations derived from crosses between XN291S and eight wheat cultivars. All F1 plants were fertile and the F2 populations segregated in either 15 : 1 or 3 : 1 fertile : sterile ratios indicating that PTSMS was controlled by one or two recessive major genes. Five wheat cultivars carried homozygous dominant alleles for fertility, whereas the other three, including ‘Chinese Spring’ (CS), carried a single homozygous dominant allele. Chromosomal location of the PTSMS gene was studied by crossing a set of CS nulli‐tetrasomic lines to XN291S. Self‐fertility of F1 hybrids XN291S/N5BT5A and XN291S/N5BT5D were significantly lower than the others. Therefore, the PTSMS gene in XN291S that differed from CS was located on chromosome 5B. Location of the second PTSMS gene needs further study.  相似文献   

3.
The cytoplasmic male sterility (CMS) system msm1 in barley is known to be thermosensitive, sometimes resulting in spontaneous fertility restoration in the absence of the corresponding restorer gene Rfm1. Here, we investigated genotypic differences concerning temperature sensitivity and the plant developmental stage at which elevated temperature induces spontaneous fertility restoration in three CMS mother lines. While one line stayed completely male sterile, a significantly higher fertility was observed in two lines after treatment from growth stage DC 41 until maturation. Microscopic analysis revealed that sterile anthers contained neither intact pollen, nor remains of aborted pollen grains, whereas pollen was visible in anthers of potentially fertile plants. We conclude that the barley CMS system affects anther and pollen development prior to meiosis. Elevated temperature during heading and flowering can lead to a spontaneous fertility restoration by reactivating pollen growth. Nevertheless, genotypic variation exists enabling the selection for stable CMS mother lines and the development of F1 hybrids with high hybridity. As spontaneous fertility restoration due to environmental effects is difficult to phenotype, further investigations will focus on the development of molecular markers for marker‐assisted selection.  相似文献   

4.
Adoption of pigeonpea hybrids in central and southern India is showing high impact with on‐farm yield advantages of >30%. The hybrid pigeonpea technology, the first in any legume crop, is based on a cytoplasmic‐nuclear male‐sterility (CMS) system. For a long‐term sustainability of hybrid programme, it is imperative that both nuclear diversity and cytoplasmic diversity are maintained among hybrid parents. In this context, a continuous search for new CMS‐inducing cytoplasms is necessary. This paper reports detection of maternal inheritance of male sterility in the progeny derived from a natural hybrid between a wild relative [Cajanus lineatus (W. & A.) Maesen comb. nov.] of pigeonpea and an unknown pigeonpea [Cajanus cajan (L.) Millsp.] genotype. In the present study, the male sterility was maintained up to BC7F1 generation by an advanced breeding pigeonpea line ICPL 99044. This male sterility inducing cytoplasm of C. lineatus was tagged as A6. In future, this CMS genetic stock can be used to develop a range of new pigeonpea hybrids with high yield and adaptation.  相似文献   

5.
Trifolium occidentale is a diploid wild relative of T. repens (white clover) with adaptation to dry, saline coastal habitats. Transfer of drought and salt‐tolerant adaptive traits to white clover could be potentially valuable if interspecific hybridization can be achieved efficiently and leads to fertile hybrid populations. To achieve hybridization, 4x plants of T. occidentale were generated. Efficient techniques for generation of 4x plants and their identification using dry pollen shape are described. Interspecific 4x F1 plants were achieved without embryo rescue. F2 populations and first backcross hybrids to white clover were also efficiently achieved. Although male and female fertility were lower than in white clover, they were adequate to produce large amounts of seed from small numbers of inflorescences. Thus, early generation interspecific hybrid prebreeding populations can be readily developed, opening the way for transfer of traits from T. occidentale to white clover.  相似文献   

6.
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   

7.
The paper deals with the cytogenetics of a new three species hybrid combination obtained as a result of crossing N. tabacum with the fertile amphiploid N. glutinosa × N. trigonophylla. The amphidiploid was established through colchicine doubling of a sterile hybrid of the same parentage in 1956. The tabacum-amphidiploid cross was made reciprocally and meiosis of both the hybrids was studied. While the N. tabacum × (glutinosa-trigonophylla) hybrid showed a pairing frequency of 6.09 bivalents (2 n of hybrid: 48) the reciprocal (glutinosa-trigonophylla) × N. tabacum, showed a mean bivalent frequency of 10.07. Other stages of meiosis also revealed differences. Pollen fertility was reduced to less than 1.0% in both and the hybrids proved to be sterile although one of them, (glutinosa-trigonophylla) × N. tabacum, exhibited a heavy setting of parthenocarpic capsules. In spite of continued failures, germination could be induced in a single seed of a backcross between N. tabacum × (glutinosa-trigonophylla) and N. tabacum.While the amphiploid of the original cross possessed predominance of glutinosa characters, the reciprocal hybrids showed a greater expression of tabacum characters.The pairing behaviour of the hybrids is discussed in the light of pairing behaviour of the same species in other hybrid combinations and a tentative assumption is drawn explaining the affinity between N. trigonophylla and N. tomentosiformis (present in the tabacum genome), confirming, to a certain extent, the statement that a relationship appears to be evident between the progenitors of the sections tomentosae and trigonophyllae, both with 12 chromosomes.
Samenvatting Met behulp van colchicinebehandeling werd in 1956 de steriele bastaard van Nicotiana glutinosa x N. trigonophylla verdubbeld. De aldus verkregen fertiele amphidiploid (welke onvatbaar was voor het tabaksmozaïek-virus) werd reciprook gekruist met N. tabacum. De uit genoemde 3 soorten opgebouwde bastaarden bezitten 48 chromosomen. Ze zijn in hoge mate steriel. Slechts 1 kiemend zaad werd verkregen van de terugkruising met N. tabacum.Terwijl de amphidiploiden van de oorspronkelijke kruising vooral glutinosa eigenschappen vertoonden, hadden de reciproke bastaarden met N. tabacum meer tabacum-kenmerken.In het gedrag van chromosomen-paring werd een bevestiging gevonden van de verwantschap tussen de 12-chromosomige voorouders van de secties tomentosae en trigonophyllae.
  相似文献   

8.
To elucidate the genetic mechanism of hybrid lethality observed in hybrids between cultivated tobacco, Nicotiana tabacum, and wild tobacco species in the section Suaveolentes, genetic analyses were conducted through the triple cross of the hybrids of wild species, including N. benthamiana and N. fragrans, and N. tabacum. N. benthamiana and N. fragrans produced only viable hybrids after crossing with N. tabacum. Subsequently, N. benthamiana and N. fragrans were crossed with N. africana, N. debneyi, and/or N. suaveolens, which produced inviable hybrids after crossing with N. tabacum. Hybrids of the wild species were obtained from four of the six cross combinations. Only when hybrid plants of N. debneyi × N. fragrans, whose hybridity was confirmed by morphological characteristics, random amplified polymorphic DNA analysis, and chromosome observation, were crossed with N. tabacum, triple hybrids were obtained and segregated 1:1 (lethal:viable). Based on these results, a single dominant gene, designated Hybrid Lethality A1 (HLA1), in N. debneyi was found to control hybrid lethality by the interaction with gene(s) on the Q chromosome in N. tabacum. This represents the first report to identify a causal gene for hybrid lethality in the genus Nicotiana.  相似文献   

9.
The reaction to Tomato spotted wilt virus (TSWV) was evaluated in 94 accessions of Nicotiana, originating from the Institute of Soil Science and Plant Cultivation tobacco germplasm collection in Pu?awy, Poland. Tests for resistance were conducted under greenhouse conditions using single TSWV isolate collected from tobacco plantation in Lublin district, Poland. The presence of the virus was verified using DAS-ELISA. SCAR markers associated with TSWV resistance gene were applied. The members of the section Alatae, the genus Nicotiana: N. alata, N. forgetiana, and Nicotiana x sanderae as well as N. tabacum cultivars: ‘Polalta’ and ‘Wiktoria’ with the TSWV resistance gene introduced from N. alata, displayed the hypersensitive reaction (HR) against TSWV (grade 0 on symptom intensity scale). In some of those accessions, the virus spread from the initially infected areas eliciting systemic hypersensitive reaction (SHR). Five accessions of N. alata and three of Nicotiana x sanderae were composed of 6.3–50.0 % of plants in which SHR symptoms appeared. In all of N. forgetiana plants HR reaction was followed by systemic infection (SHR). In N. tabacum ‘Wiktoria’ 21.1 % of plants showed HR reaction, while the remaining were susceptible (S). All of the genotypes which responded with HR or SHR reaction to TSWV infection demonstrated the presence of SCAR markers linked to the resistance gene. The remaining eighty tested accessions were identified as being susceptible upon exposure to TSWV.  相似文献   

10.
Nicotiana glauca, a wild relative of Nicotiana tabacum, is an attractive potential source of black root rot (Thielaviopsis basicola)‐resistant germplasm. Moreover, it shows a resistance or tolerance to PVY, TEV, anthracnose and powdery mildew. In this study its potential as a source of resistance to black root rot caused by Th. basicola was investigated. Nicotiana glauca GG (2n = 2x = 24) was crossed as male with two N. tabacum TT (2n = 4x = 48) flue‐cured cultivars: ‘BY103’ and ‘K 326’, both of which are susceptible to black root rot. Amphihaploid F1 TG (2n = 3x = 36), amphidiploid TTGG (2n = 6x = 72) and sesquidiploid TTG (2n = 5x = 60) hybrids were obtained. The resultant sesquidiploid hybrids were used as maternal components in backcrossing to N. tabacum and a segregating post‐sesquidiploid TTg (2n = 5x = 52–54) offspring was obtained. Amphihaploids exhibited a level of resistance to black root rot characteristic of N. glauca. The expression of resistance varied in the sesquidiploid generation, possibly reflecting cytological instabilities in that progeny. A wide variation in response to black root rot was found for post‐sesquidiploids a clear reflection of extensive chromosome segregation in that hybrid generation.  相似文献   

11.
李曙光  赵团结  盖钧镒 《作物学报》2010,36(7):1061-1066
利用大豆质核互作雄性不育系NJMCS3A的质、核供体亲本N21566和N21249构建F2和BC1F1育性分离群体进行雄性育性的遗传分析与基因定位。结果表明, F1正反交可育,F2和BC1F1的可育株与不育株分离比例经χ2测验分别符合3∶1和1∶1,表明NJCMS3A供体亲本雄性育性由一对基因控制,可育等位基因为显性。该基因可能是NJCMS3A的一个恢复基因。选用793对SSR引物对F2和BC1F1群体分别进行育性基因定位,发现该育性基因位于O连锁群上,在Satt331和Satt477标记之间,与Satt331、CSSR133和Satt477标记距离的次序一致,分别为8.1~10.4 cM、11.4~16.4 cM、13.3~19.2 cM。  相似文献   

12.
In Brassica oleracea, production of F1 hybrid seeds mainly makes use of the improved Ogura cytoplasmic male sterile (CMS) line. However, reliance on one particular line is a risk, and it would be advantageous to develop other CMS lines. In this study, we transferred Diplotaxis erucoides cytoplasm to B. oleracea cultivars using an alloplasmic B. rapaCMS line as a bridge plant to avoid incompatibility between donor and recipient plants. The new B. oleraceaCMS lines, which were derived by four generations of backcrossing, had small rudimentary anthers with no pollen grain and showed complete male sterility. There was no functional defect in other floral organs, and the ability to receive normal pollen did not appear to be impaired. Moreover, the B. oleraceaCMS lines carrying D. erucoides cytoplasm had larger leaf areas and a normal plastochron. As a consequence, the B. oleraceaCMS lines carrying D. erucoides cytoplasm have the potential to be valuable alternatives for use in commercial B. oleracea hybrid seed production.  相似文献   

13.
The development of transgenic oilseed Camelina sativa (2n = 40) and the potential for hybridization with its weedy relative Capsella bursa‐pastoris (2n = 36) necessitates a careful evaluation of the reproductive compatibility between the species. Here, we conducted over 1800 crosses (emasculation and manual pollination) to examine the ability of 10 Canadian C. bursa‐pastoris (♀) accessions to hybridize with five accessions of C. sativa (♂). Seven hybrids were confirmed among 586 putative hybrids screened with species‐specific markers, indicating a hybridization rate of 1.5 hybrids per 10 000 ovules pollinated. All seven hybrids had intermediate DNA content compared to their parents, were morphologically distinct, had low (1.9%) pollen fertility and failed to produce selfed or backcrossed seed. Given the abundance of C. bursa‐pastoris along field margins, hybrids will likely be generated in the wild, but they will be unable to establish lineages unless fertility is restored. The large number of crosses and the diversity captured by the use of multiple accessions resulted in strong statistical power and a high degree of confidence in the estimated hybridization rate.  相似文献   

14.
Wild Lens taxa are invaluable sources of useful traits for broadening genetic base of cultivated lentil. Nine inter‐sub‐specific and interspecific crosses were made successfully between cultivated (Lens culinaris ssp. culinaris) and wild lentils (L. culinaris ssp. orientalis, odemensis, lamottei and ervoides). The effect of species groups, day length and temperature on crossability in lentils was evident under normal winter sowing in New Delhi and in summer Himalayan nursery at Sangla in Himachal Pradesh, India, although pollen fertility assessed in all the cross‐combinations showed no significant variation. True hybridity of nine inter‐sub‐specific and interspecific crosses was confirmed through morphological and molecular (ISSR) markers, in which three of 120 primers could confirm the hybridity of all the crosses. All cross‐combinations were also studied for important quantitative traits related to yield. The range, mean and coefficient of variation were estimated in parental lines, F1 and F2 generations to determine the extent of variability generated in cultivated lentils through the introgression of genes from wild L. taxa. A high level of heterosis was observed in F1 crosses for important traits studied. Substantially higher variations for seed yield and its attributing traits were exhibited in F2 generations indicating transgressive segregation. The results of the present investigation revealed that wild L. taxa can be successfully exploited for lentil improvement programmes, and the variations generated could be easily utilized for broadening the genetic base of cultivated lentil gene pool for improving the yield as well as wider adaptation.  相似文献   

15.
The cytoplasmic male‐sterility (CMS)/fertility‐restoration system is important for hybrid sunflower (Helianthus annuus L.) seed production. The objective of this study was to characterize two novel alloplasmic CMSs, designated CMS GRO1 and CMS MAX3, with defective anthers, narrow disc florets with no swollen corolla, and short, narrow ray flowers derived from two tetraploid amphiploids (AMPs). Among 26 tested lines, only AMP Helianthus cusickii/P 21 and HA 410 failed to restore male‐fertility. Segregation of CMS, male‐fertile plants and plants with reduced male‐fertility was observed both in the testcross progeny of a six line half‐diallel cross of F1s with CMS MAX3 and in an F2 population of CMS GRO1 × RHA 274. Male‐fertility restoration was controlled by at least two dominant genes. Detailed analysis of the mitochondrial genes may provide insight into the differences between these CMSs and other CMS lines. The new CMSs will facilitate the studies of the incompatibility between cytoplasmic and nuclear genes, especially for the alloplasmic CMS involving perennial species, and also provide unique ornamental flower types and CMS sources for hybrid sunflower breeding.  相似文献   

16.
Cytoplasmic male sterility (CMS) system based on the cytoplasm from Moricandia arvensis (mori) was investigated for fertility restoration and agronomic potential. Fertility restorer gene for mori CMS was introgressed from cytoplasm donor species as all the evaluated Brassica juncea genotypes (155) acted as sterility maintainers. The allosyndetic pairing between Ma and the A/B genome chromosomes in the monosomic addition plants (2n= 18II + 1Ma) facilitated the gene introgression. Partial fertility restoration (43–52% pollen grain stainability) in F1 hybrids and absence of segregation for male sterility in F2 progenies suggested gametophytic control of fertility restoration. The pollen fertility in the F1 hybrids was, however, sufficient to ensure complete seed set upon bag selfing. Introgression from M. arvensis also helped in correction of chlorosis associated with mori cytoplasm in CMS and fertile alloplasmic B. juncea plants. Yield evaluation of thirty F1 hybrids having the same nuclear genotype but varied male sterilizing cytoplasms (mori, oxy, lyr, refined ogu), in comparison to respective euplasmic hand bred control hybrids, allowed an estimate of yield penalty associated with different CMS systems. It ranged from 1.8% to 61.6%. Hybrids based on cytoplasmically refined ogu were most productive followed by those based on cytoplasmically refined mori CMS. The male sterility systems emanating from somatic hybridization were found superior than those developed from sexual hybridization.  相似文献   

17.
The potential for gene flow between Camelina sativa, a promising edible and industrial oil crop in Canada, and its wild North American relatives C. alyssum, C. microcarpa and C. rumelica subsp. rumelica, was investigated. Sequence analysis of the nuclear ribosomal internal transcribed spacer region (ITS) was used to differentiate Camelina species and/or accession‐specific nucleotide markers and identify interspecific F1 hybrids. ITS analysis identified hybrids in progeny of C. alyssum × C. sativa, C. microcarpa accession 36010 × C. sativa and C. sativa × C. rumelica subsp. rumelica. Seed set on C. alyssum × C. sativa F1 and F2 progeny was similar to the parents; few seeds were produced on hybrid progeny of C. microcarpa accession 36010 × C. sativa and C. sativa × C. rumelica subsp. rumelica. The study provided evidence that should the species have sympatric distributions and overlapping flowering periods, gene flow between C. sativa and its wild North American relatives is possible and that it would most likely occur with C. alyssum given the high fertility of the F1 hybrids recovered.  相似文献   

18.
Vitamin A deficiency in humans is a widespread health problem. Quality protein maize (QPM) is a popular food rich in lysine and tryptophan, but poor in provitamin A (proA). Here, we report the improvement of an elite QPM inbred, HKI1128Q for proA using marker‐assisted introgression of crtRB1‐favourable allele. HKI1128 was one of the parental lines of three popular hybrids in India and was converted to QPM in our earlier programme. Severe segregation distortion for crtRB1 was observed in BC1F1, BC2F1 and BC2F2. Background selection by 100 SSRs revealed mean recovery of 91.07% recurrent parent genome varying from 88.78% to 93.88%. Across years, introgressed progenies possessed higher mean β‐carotene (BC: 9.22 µg/g), β‐cryptoxanthin (BCX: 3.05 µg/g) and provitamin A (proA: 10.75 µg/g) compared to HKI1128Q (BC: 2.26 µg/g, BCX: 2.26 µg/g and proA: 3.38 µg/g). High concentration of essential amino acids, viz. lysine (mean: 0.303%) and tryptophan (0.080%) in endosperm, was also retained. Multi‐year evaluation showed that introgressed progenies possessed similar grain yield (1,759–1,879 kg/ha) with HKI1128Q (1,778 kg/ha). Introgressed progenies with higher lysine, tryptophan and proA hold immense potential as donors and parents in developing biofortified hybrids.  相似文献   

19.
K. C. Sink  J. B. Power 《Euphytica》1978,27(3):725-730
Summary Extensive pollinations were made in attempts to produce selected intergeneric or interspecific hybrids using Nicotiana and Petunia species that exhibit potential for somatic hybridization. Pollination between pairs of species was done by standard and bud-pollination methods. Nicotiana alata or N. tabacum when pollinated reciprocally with selected Petunia species failed to produce hybrids. Likewise, no interspecific hybrids were obtained between Petunia parviflora and 4 Petunia species or P. hybrida. The type of incongruity existing between these species is discussed in relation to the production of hybrids by standard In vitro techniques as compared to somatic hybridization.On leave from the Department of Horticulture, Michigan State University, E. Lansing, Michigan, USA. supported by a European Molecular Biology Organization (EMBO) fellowship and The Fred C. Gloeckner Foundation, N. Y., USA.Supported by the Agricultural Research Council.  相似文献   

20.
In pepper (Capsicum annuum), the major genes (R‐genes) Me1 and Me3 confer resistance against root‐knot nematodes (Meloidogyne spp.). The combination of R‐genes and quantitative resistance factors in the same genotype is considered a good breeding strategy for increasing the durability of R‐genes. To ascertain this hypothesis, five pepper inbred lines, differing in their quantitative resistance level, were combined with Me1 or Me3 genes in F1 hybrids. The resistance of inbred lines and F1 hybrids was evaluated in a greenhouse with soil naturally infected by M. incognita in two successive growing years. In both years, lines carrying Me3 were less infected by the nematode when combined with quantitative resistance. An increase in nematode infection was observed in the second growing year in lines carrying Me1 or Me3, independently of quantitative resistance. The infection level recorded in inbred lines without R‐genes was similar in both years. The effectiveness of quantitative resistance controlling M. incognita is confirmed in greenhouse conditions, although the durability of Me1 and Me3 when combined with quantitative resistance factors was not seen to increase.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号