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1.
Summary Chloroplast DNA restriction fragment lenght polymorphisms (RFLP) were used to examine the taxonomic relationships of cultivated and wild lentil (Lens Miller) species and identify the extent of genetic variation in this genus. Twelve accessions representing all Lens subspecies were digested with four hexanucleotide-recognizing restriction endonucleases. These digests randomly surveyed 540 base pairs, or 0.4% of the approximately 125 kilobase lentil chloroplast genome. A high degree of gragment length conservation was seen among members of crossability group I, i.e., L. c. ssp. culinaris, L. c. ssp. orientalis and L. c. ssp. odemensis. Accessions of the two subspecies comprising crossability group II, i.e., L. n. ssp. nigricans and L. n. ssp. ervoides, showed the greatest amount of variation when compared to the cultivated lentil, L. c. ssp. culinaris. Limited variation was observed within subspecies except for L. n. ssp. nigricans, where accessions of the normal cytotype were highly polymorphic to those of the differentiated cytotype. Chloroplast DNA RFLPs reaffirm hypotheses that propose L. c. ssp. orientalis as the progenitor to the cultivated lentil. The implications of this study on taxonomy and genetic resources is also discussed.  相似文献   

2.
Seed weevil (Bruchus spp.) is one of the most damaging pests to lentil crop, and the current chemical treatments to control this insect present numerous disadvantages. In this work, we have searched for resistant or almost resistant lentil cultivars to be used as potential sources of genes for resistance to bruchids as a more sustainable and environmentally friendly approach to diminish harvest loss. Thus, a lentil germplasm collection of 571 accessions from 27 different countries, and including wild species was screened for susceptibility to seed bruchids under natural field conditions in Central Spain. Infestation was evaluated in comparison with a check (lentil cultivar ??Lyda??) according to the number of eggs per pod and the infestation rate in seeds (IR). A large variation of IR (0?C70?%) was observed among accessions although, in general, wild species were consistently less affected by bruchids than the check. A total of 32 accessions, including Lens culinaris Medikus subsp. culinaris, Lens culinaris Medikus subsp. orientalis (Boiss.) Ponert, Lens nigricans (M. Bieb.) Godr., and Lens lamottei Cezfr., showed lower infestation rates than the check and were selected as potential sources of resistance to this pest. Potential mechanisms of resistance of selected accessions and their inclusion in a breeding program are outlined.  相似文献   

3.
Wild Lens species/subspecies are a potential source for increasing genetic diversity in cultivated lentil. Four intraspecific crosses were attempted between cultivated and wild lentils. Viable hybrids were produced between L. culinaris ssp. culinaris × L. culinaris ssp. orientalis and L. culinaris ssp. culinaris × L. culinaris ssp. odomensis. Normal meiosis and pollen fertility were observed in the first set of crosses, whereas chromosomal abnormalities and reduced pollen fertility were observed in the second set of crosses. These crosses were also studied for some quantitative traits. The range, mean and coefficient of variation were calculated in parents, F1, F2 and BC1 generations to determine the extent of variability generated in the cultivated lentil through introgression of genes from wild lentil. The cultivated lentil × L. culinaris ssp. orientalis crosses showed substantially higher variability for all the traits than crosses involving cultivated lentil ×L. culinaris ssp. odomensis. The results of the present study indicated that these wild subspecies can be exploited for breeding purposes and their variation can easily be utilized to widen the genetic base of the cultivated lentil.  相似文献   

4.
Variation in the ribosomal RNA units of the generaLens andCicer   总被引：2，自引：0，他引：2  
Summary Investigation of the organization of the tandemly repeated 5S and 18–25S ribosomal RNA (rRNA) genes was carried out on members of the generaLens andCicer using restriction endonuclease digestion and Southern hybridization. The 5S rRNA unit (gene+spacer) inLens (0.38 to 0.50 kb) andCicer 0.50 to 0.44 kb) is the largest among the legumes. InL. nigricans andL. culinaris ssp.odemensis a second repeat size was detected. Restriction maps for the 18–25S units ofLens andCicer species were developed. The 18–25S rRNA unit varied from 8.3 to 9.8 kb inLens and 10.5 to 11.4 kb inCicer. The only detectable variability in theLens andCicer 18–25S rRNA unit was in the length of the intergenic spacer (IGS) region, except for a HindIII site in the IGS region ofL. nigricans ssp.nigricans and in allCicer species.Similarities in the size of both 5S and 18–25S rRNA units were noted betweenL. culinaris ssp.culinaris andL. culinaris ssp.orientalis, which supports previous evidence thatL. culinaris ssp.orientalis is the progenitor of the cultivated lentil. Differences in the arrangement of both 5S and 18–25S rRNA units were noted betweenL. nigricans ssp.nigricans andL. nigricans ssp.ervoides, indicating either divergent evolution of these subspecies or alternatively incorrect taxonomy.On the basis of the size of the 5S rRNA unit,C. bijugum, C. chorassanicum andC. echinospermum formed a group with a slightly smaller unit than the otherCicer species. Similarities in the length of both 5S and 18–25S rRNA units ofC. arietinum andC. reticulatum possibly confirmC. reticulatum as the progenitor ofC. arietinum. Cicer cuneatum has a smaller 18–25S rRNA unit than the otherCicer species as a result of a smaller intergenic spacer.  相似文献   

5.
Summary A survey of allozyme polymorphism at 11 loci was carried out on 439 accessions from the genus Lens. This comprised 153 Lens culinaris subsp. orientalis, 35 L. odemensis, 117 L. ervoides, 32 L. nigricans, 2 of a differentiated cytotype of L. nigricans and 100 landrace accessions of the cultivated lentil (L. culinaris subsp. culinaris), from 10 different countries. The aim of the survey was to determine intra-specific genetic diversity and species relationships, based on phylogenetic and phenetic analyses, particularly regarding the position of L. odemensis and the differentiated cytotype of L. nigricans. Diversity was described by three statistics. The level of diversity in the cultivated taxon was lower than in any of the wild species according to two of these statistics, the percentage of polymorphic loci and mean number of alleles per locus. For the third measure (Nei's mean genetic diversity) it was only greater than L. ervoides. Genetic diversity statistics of the wild species indicated differences in the nature of between-population genetic diversity within the different taxa. Phylogenetic analysis suggests that L. odemensis and L. ervoides evolved from a common ancestor, and L. culinaris subsp. orientalis subsequently evolved from L. odemensis. Phenetic analysis, however, places L. odemensis closer to L. culinaris subsp. orientalis than to L. ervoides. Nei's mean genetic distance of L. odemensis from both L. culinaris subsp. culinaris (0.204) and L. culinaris subsp. orientalis (0.110) was greater than the distance between them (0.062). This evidence is not conclusive in determining whether L. odemensis should retain its specific status. Further crossability studies should be carried out on a range of genotypes to assess the potential for gene flow. The evidence presented shows the differentiated cytotype of L. nigricans to be quite distinct from other L. nigricans accessions, both phenetically and phylogenetically. This indicates that the differentiated cytotype of L. nigricans may constitute a new taxon. Discriminant function analysis reveals that isozymes may be useful in validating species classification.  相似文献   

6.
G. Ladizinsky 《Euphytica》1979,28(1):179-187
Summary Following hybridization experiments and cytogenetic analysis of interspecific hybrids three chromosome interchanges were found between the cultivated lentil L. culinaris and L. nigricans, and only one between the cultivated species and L. orientalis. This indicates that the latter species is more likely to be wild progenitor of lentil. The partial fertility of the interspecific hybrids indicate further that both L. nigricans and L. orientalis should be included in the wild genepool of lentil, and their variation can be exploited by relatively simple hybridization techniques. The wild lentils L. orientalis and L. nigricans are morphologically very similar but reproductively strongly isolated from one another by the albino seedling of their hybrids. It has been suggested that the populations of L. orientalis that gave rise to the cultivated lentil still possess a similar chromosome arrangement as in L. culinaris and are also capable of forming normal hybrids with L. nigricans. According to these considerations it is unlikely that lentil originated from populations at the south western corner of the distribution area of L. orientalis.  相似文献   

7.
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   

8.
Summary An analysis of the variability for genes encoding seven isozyme systems and storage proteins in a collection of cultivated and wild accessions of Lens is reported. The collection, which is part of the Spanish INIA Cenebank, contains the ssp. culinaris, orientalis, odemensis, nigricans and ervoides, and presents a high degree of genetic diversity both within and between the accessions. A total 25 loci were examined; of these, 18 were polymorphic (the 7 genes encoding storage proteins, and the following isozyme loci: Acp-1, Acp-2, Cpx-1, Cpx-2, Aat-p, Aat-m, Lap-1, Mdh-2, Mdh-3, Mdh-4 and 6pgd-p) and 7 were monomorphic (Aat-mb, Aat-c, Mdh-1, Mdh-5, 6pgd-2, Pgm-c and Pgm-p). The phylogenetic relationships between subspecies were analyzed using the allelic frequencies. The study suggests that orientalis and odemensis share more biochemical characters than the other subspecies, and that those subspecies keep an intermediate position between Lens culinaris and Lens nigricans.  相似文献   

9.
G. Ladizinsky 《Euphytica》1985,34(2):539-543
Summary Seeds of the cultivated lentil are capable of germinating shortly after maturation. The seed dormancy of wild lentil species is due to a hard seed coat. In crosses between the cultivated species L. culinaris and its wild progenitor L. orientalis the hard seed coat of the wild species was controlled by a single recessive gene in homozygous condition. In a cross between the wild species L. ervoides and L. culinaris the hard seed coat of L. ervoides was controlled by a single dominant gene. The significance of the genetics of seed coat hardness in the domestication of lentil is briefly discussed.  相似文献   

10.
Wild Lens taxa are a reservoir of useful rare genes/alleles for widening the genetic base and synthesis of a new gene pool of lentil. To maximize and sustain lentil production, new gene sources are needed to be identified and incorporated into cultivated background. This needs a comprehensive approach to accumulate favourable alleles from distantly related germplasm for widening of the cultivated gene pool and would be the most appropriate strategy to solve the various problems associated with stressed crop production and plateaued yields. Furthermore, expansion of deeper understanding of lentil genomics along with extensive research undertaken in other crop species can provide suitable guidelines to cover the distribution of Lens genus and component gene pools for further remarkable progress in lentil genetic improvement. This review aims at the genus Lens distribution and gene pools, crop germplasm conserved in ex‐situ and in‐situ collection, wild species characterization and evaluation for useful traits of interest to solve production‐related problems, highlight useful gene sources present in different gene pools and the progress achieved for widening the genetic base of cultivated varieties of lentil through wide hybridization and exploring lentil genomics.  相似文献   

11.
Wild relatives are a potential source of genetic diversity to lentil (Lens culinaris Medik). The objective of this research was to obtain viable interspecific hybrids between the domesticated lentil and its wild relatives. The paper details the results of a number of interspecific crosses among L. culinaris, L. orientalis, L. odemensis, L. ervoides and L. nigricans. Viable hybrids were produced between L. culinaris × L. orientalis, L. culinaris × L. nigricans, L. culinaris × L. ervoides and between L. culinaris × L. odemensis. Further viable hybrids were obtained between L. culinaris and L. ervoides, which have the potential to be a ‘bridge’ in hybridization to L. culinaris for specific L. nicrigans lines which proved recalcitrant in L. culinaris × L. nigricans crosses. This is the first time that four wild species of lentils have been used successfully in hybridization with cultivated lentils, and viable hybrids produced. This paper also suggests that the artificial supplement of GA3, hormone is needed after fertilization for the normal growth of the hybrid embryo, possibly as the natural GA3 production is restricted with alien pollinations in cultivated lentils in both F1 and backcross hybrids.  相似文献   

12.
Genetic analysis and linkage study of seed weight in lentil   总被引：1，自引：0，他引：1  
Summary The genetics of seed weight was studied in crosses between the cultivated lentil L. culinaris and the wild species L. orientalis and L. ervoides. Seed weight was found to be under polygenic control with additive and dominant gene action and with partial dominance of low seed weight alleles. High heretability estimates were obtained in the analysed crosses. Nuclear-cytoplasmic interaction was found to affect seed weight in crosses involving accession No.138 of L. orientalis. Factors affecting seed weight were linked to morphological and DNA markers distributed over several linkage groups. High seed weight in segregating generations were usually associated with alleles of marker loci originated from the cultivated parent. Factors enhancing seed weight were detected in accession No.138 of L. orientalis, indicating the potential of wild genetic resources for seed weight improvement in lentil.  相似文献   

13.
R. Fratini    P. García    M. L. Ruiz 《Plant Breeding》2006,125(5):501-505
Morphological and in vitro germination characteristics of pollen altogether with pistil and style length were analysed, so as to carry out a morphological comparison between different lentil (Lens culinaris Medik.) cultivars and wild species, as well as to correlate the morphological and functional statistics with data regarding crossing success. Pollen length and width in the different genotypes were found to have a positive and highly significant correlation with pistil and style length and in vitro pollen tube length. A cluster analysis detected two different plant groups, namely, (i) large‐seeded L. culinaris (macrosperma), and (ii) a second group formed by two subgroups, a first subgroup with L. ervoides standing alone and a second subgroup including small‐seeded L. culinaris (microsperma) and the wild L. culinaris ssp. orientalis, L. odemensis, L. nigricans. A high and significant correlation was detected between crossing success and phenotypic similarity (r > 0.98; P < 0.05), therefore implying that phenotypic similarity, based on pollen morphology and in vitro pollen length together with pistil and style length, is a good predictor of hybridization success.  相似文献   

14.
Summary The wild lentil, L. nigricans is cross compatible with the cultivated species. Chromosome pairing in their F1 hybrids is highly irregular due to a difference of three translocations between the parental species. However, the hybrids are partially fertile and in the F2 populations there is a marked improvement in fertility. About 19% of the F2 plants were meiotically stable, fully fertile and their chromosome arrangement was similar to that of the cultivated species. All these are clear indications for the possibility of rapid introgression between the two species and hence systematic screening of L. nigricans for traits of economic value is fully justifiable.  相似文献   

15.
Seed dormancy is one of the most important parameters affecting the malting process and pre-harvest sprouting in barley (Hordeum vulgare L.). Variation of seed dormancy in 4365 cultivated and 177 wild barley (ssp. spontaneum) accessions derived from different regions of the world was investigated in Okayama University, Kurashiki, Japan. Seed dormancy of each accession was estimated from their germination percentages at 0, 5, 10 and 15 weeks post-harvest after-ripening periods. All of the wild barley accessions showed less than 10% germination at 0 week after-ripening period. Level of seed dormancy in 4365 cultivated barley accessions showed a clear geographical differentiation. Seventy seven percent of Ethiopian accessions showed high germination percentages, while 86% of Japanese, Turkish and North African accessions showed low germination percentages at 0 week after-ripening period. A half diallel cross using eleven barley accessions with different level of dormancy revealed that seed dormancy was predominately controlled by additive gene effects. These results suggest that large genetic diversity for seed dormancy in barley is explained as different levels of additive accumulation of genetic factors. Barley varieties showing appropriate dormancy could be developed by crossing among barley germplasm accessions used in the present study.  相似文献   

16.
Summary We report on the inheritance of 11 morphological markers and 17 isozymes in lentil (Lens culinaris). The monogenic inheritance of 11 morphological markers and 11 isozymes is confirmed. The inheritance of six isozymes (Aco-2, Enp, Est-3, Est-4, Lap-3, and Mdh-m) is reported for the first time in lentil. This brings the total number of described genes in lentil to 78. Cases of disturbed segregation were more frequent than expected by chance. It is suggested that disturbed segregation was in most cases caused by linkage with a piece of chromosome that showed preferential elimination in crosses between Lens culinaris ssp. odemensis and other subspecies. The prevalence of disturbed segregation in crosses with Lens culinaris ssp. odemensis could limit the usefulness of this subspecies in genetic and linkage studies.  相似文献   

17.
This study was conducted to determine if Brassica germplasm bulks created and maintained by the USDA-ARS North Central Plant Introduction Station (NCRPIS) were made with genetically indistinguishable component accessions and to examine newly identified putative duplicate accessions to determine if they can be bulked. Using ten microsatellite primer pairs, we genotyped two bulks of B. rapa L. ssp. dichotoma (Roxb.) Hanelt comprising four accessions and three bulks of B. rapa L. ssp. trilocularis (Roxb.) Hanelt comprising fourteen accessions, as well as four pairs of putatively duplicate accessions of B.␣napus L. Assignment tests on ten individual plants per accession were conducted using a model-based clustering method to arrive at probabilities of likelihood of accession assignment. The assignment tests indicated that one of the two bulks of B. rapa ssp. dichotoma involves genetically heterogeneous accessions. It was observed in the B. rapa ssp. trilocularis bulks that the component accessions could be differentiated into groups, with misassignments observed most frequent within groups. In B. napus, only one of the four pairs of putative duplicates showed significant genetic differentiation. The other three pairs of putative duplicates lack differences and support the creation of bulks. The results of the assignment tests were in agreement with cluster analyses and tests of population differentiation. Implications of these results in terms of germplasm management include the maintenance and/or re-creation of some Brassica germplasm bulks by excluding those accessions identified as being unique in this study.  相似文献   

18.
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   

19.
Wild species which are crossable to cultivated pea, lentil, and chickpea have been collected and are maintained in major germplasm collections throughout the world. Wild species of Vicia crossable to the cultivated faba bean have not been found. The primary, secondary, and tertiary gene pools of the cool season food legumes represent potential genetic diversity that may eventually be exploited in cultivated types to overcome biotic and abiotic stresses. Technical difficulties in obtaining hybrids beyond those within the primary gene pool is a major obstacle. Reproductive isolation, embryo breakdown, hybrid sterility, and limited genetic recombination are major barriers to greater use of wild germplasm. Conventional crossing has been successful in producing interspecific hybrids in Lens, Cicer and Pisum and those hybrids are being evaluated for desired recombinants. In vitro culture of hybrid embryos has been successful in overcoming barriers to wider crosses in Lens. The successful transfer of genes from wide sources to cultivated types can be assisted by repeated backcrossing and selection designed to leave behind undesired traits while transferring genes of interest. Molecular marker assisted selection may become a valuable tool in the future use of wild species. In general, too little is known about the possible genetic variation available in wild species that could be valuable in developing resistance to biotic and abiotic stresses. Current efforts on the use of wide hybridization in the cool season food legumes are reviewed and discussed.  相似文献   

20.
Summary The increasing popularity of organic agriculture and health food products has led to a renewed interest in hulled wheat species such as emmer (Triticum turgidum ssp. dicoccumSchubler). Knowledge on agronomic and quality traits is required for effective and efficient use of germplasm collections in breeding programs. The objective of this study was to estimate agronomic and grain quality traits of emmer wheat cultivated in Italy. A total of 20 emmer accessions consisting of landraces, breeding lines or cultivars selected from landraces and modern cultivars were examined under low input conditions. The study was conducted for three successive years (2002–2004) at one location of Southern Italy (Foggia). The entries were characterized for agronomic and qualitative traits [grain yield (t ha−1), thousand grain weight (g), test weight (kg hl−1), grain protein content (%), HMWG composition, dry gluten content (%), gluten index and yellow index, alveograph indices and Total Organic Matter (TOM) on cooked pasta]. The results showed a large genetic variability for most of the traits measured and, even if most of the accessions showed inferior bread- and pasta-making performance, modern cultivars exhibited improved quality traits with some potential to perform healthy and tasty food.  相似文献   

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