排序方式: 共有7条查询结果,搜索用时 218 毫秒
1
1.
2.
Abnormal hybrid seedling development hinders attempts to introgress diverse germplasm in common bean (Phaseolus vulgaris L.) breeding programs. In this study, the hypothesis that DL1 and DL2 loci control abnormal seedling development both in Phaseolus vulgaris L. intraspecific hybrids and in P. vulgaris×P. acutifolius A. Gray interspecific hybrids was tested. Hybrids from crosses between six P. vulgaris lines (two Andean dl1 d1, DL2DL2, two Mesoamerican DL1DL1 dl2 dl2, and two facilitators dl1dl1, dl2dl2) and P. vulgaris cultivar Ex Rico 23 developed normally, indicating that Ex Rico 23 has the facilitator genotype dl1, dl1, dl2dl2. Previous studies have shown that Ex Rico 23 ×P. acutifolius results in abnormal seedlings, but ‘ICA Pijao’, also dl1, dl1 dl2dl2, ×P. acutifolius results in normal seedlings. Neither the Andean nor the Mesoamerican lines crossed successfully with P. acutifolius, but crosses between one of the two facilitators (G3807) and P. acutifolius resulted in normal seedlings. These results support the hypothesis that different loci control intra- and interspecific hybrid seedling development. 相似文献
3.
The tepary bean (Phaseolus acutifolius A. Gray) is grown mainly in and regions of Mexico and the southwestern U.S. as a subsistence crop by small farmers. It is also a store of genetic variability for traits such as disease and pest resistance and stress tolerance to improve the common bean (P. vulgaris L.). To determine geographic patterns of variation and the influence of domestication on genetic variability, the genetic diversity of phaseolin, the major seed storage protein, was characterized among 55 wild and 8 cultivated teparies using polyacrylamide gel electrophoresis. Fifteen electrophoretic phaseolin patterns were identified among wild forms, whereas only one pattern was exhibited by cultivars. This result suggests a single domestication in this species leading to a strong reduction in diversity. An additional finding is the divergence m phaseolin types between populations east and west of the Sierra Madre Occidental mountains. 相似文献
4.
Zinhle Babongile Mhlaba Beyene Amelework Hussein Shimelis Albert Thembinkosi Modi 《Acta Agriculturae Scandinavica, Section B - Plant Soil Science》2018,68(7):608-618
Understanding the genetic relationship of crop ideotypes is essential for genetic analysis and breeding. The objective of this study was to determine genetic differentiation present among 20 selected tepary bean (Phaseolus acutifolius A. Gray) genotypes using morphological traits and simple sequence repeat (SSR) markers in order to identify genetically unique parental lines to develop breeding populations. Phenotypic diversity was estimated using Shannon-Weaver diversity index (H’), principal component analysis (PCA) and cluster analysis (CA). Genotypic diversity was estimated using Jaccard's genetic distances and CA. Shannon-Weaver diversity index values for the studied morphological traits ranged from 0.89 to 0.99, with a mean of 0.95 revealing high phenotypic differences among test genotypes. PCA identified four useful principal components (PC's) which contributed to 73% of the total phenotypic variation of collections. PC1 accounted for 28% of the total variation correlated to dry shoot mass and number of pods per plant. PC2 correlated with number of seeds per pod, grain yield and harvest index and contributed to 21% of total variation. The mean observed (Ho) and expected (He) heterozygosity values were 0.45 and 0.51, respectively revealing moderate genetic differentiation among genotypes. The mean polymorphic information content was 0.52, suggesting efficient discriminatory power of the SSR loci useful in future tepary bean genetic diversity analysis. The current study revealed moderate genetic differentiation among the studied tepary bean genotypes. Morphological traits and SSR markers well-correlated in allocating the tepary bean genotypes. The following genotypes were genetically distinct: G40201, G40237, G40068, G40033 and G40063 which are recommended for further crosses, selection and population development. 相似文献
5.
The tepary bean (Phaseolus acutifolius A. Gray) is a desirable genetic resource for incorporation of improved disease, pest, and stress resistance into common bean (P. vulgaris L.). Reproductive barriers separate the two species and the degree to which tepary genes may be introgressed into the common bean genome has not been well described. Greenhouse studies of gene introgression through recurrent back-crossing to common bean were performed using two first backcross (BC1) and nine second backcross (BC2) populations. The truncate primary leaf characteristic of tepary bean was readily observed but the short primary leaf petiole and narrow bract tepary traits were infrequently observed in both BC1 and BC2 populations. In one BC, population high frequencies of adaxial stomata (characteristic of P. acutifolius) and the presence of a 30 kD cotyledon polypeptide from P. acutifolius were also observed; however, a diapho-rase isozyme from P. acutifolius appeared to be eliminated from BC1 progeny at a high rate whereas 6-phosphogluconate dehydrogenase alleles appeared to be transmitted normally. The expression of tepary primary leaf truncate morphology and bract width were correlated with decreased fertility in one of the two BC1 populations. Given suitable parental genotypes and population sizes it should be possible to transfer genes from P. acutifolius to P. vulgaris, especially in regions of the genome which are not associated with inviability or sterility. It will be difficult to transfer factors from certain regions of the tepary genome which are preferentially eliminated during introgression. 相似文献
6.
The tepary bean (Phaseolus acutifolius) is the object of renewed interest because it possesses some interesting agronomic attributes such as tolerance to drought and salinity. In order to gain a better understanding of the organisation of its genetic diversity, we have examined patterns of diversity for nine polymorphic enzyme systems representing 12 loci, in a sample of 55 wild and 8 cultivated accessions. Several geographic patterns were identified, including an East-West differentiation, (across the Sierra Madre Occidental mountains), a North-South differentiation, and a localized differentiation. Wild teparies displayed a higher number of polymorphic loci, as well as a higher number of alleles per polymorphic locus compared to cultivars, consistent with previous observations indicating a reduction of phaseolin diversity on domestication. No clearcut separation with respect to isozyme differentiation was observed between P. acutifolius var. tenuifolius and var. acutifolius, further questioning the validity of this taxonomic separation based on leaflet shape. 相似文献
7.
Crosses were performed between nine Phaseolus vulgaris lines (as females) and seven P. acutifolius lines (as- male to examine parental compatibility for the production of vigorous hybrid And backcross plants, in vitro embryo rescue techniques were required to secure hybrid and backcross proseny following interspecific crossing. Seedling development appeared to be dependent on which allele the P. vulgaris parent carried at an interspecific incompatibility locus. Seven of the nine P. vulgaris lines tested carried an allele at this locus which interacted with a nuclear factor in the P. acutifolius genome resulting in stunted, sub-lethal hybrids. The lines, ICA pijao' and ‘Sacramento Light Red Kidney’ did not carry this allele and produced vigorous hybrid progeny in combination with all P. acutifolius parents. Intensive backcrossing produced progeny which also segregated for sub-lethal and viable plant development. The observed segregation patterns suggest that a bridge crossing scheme would facilitate the introgression of P. acutifolius germplasm into incompatible P. vulgaris lines. Similarities, with an intraspecific incompatibility system are discussed. 相似文献
1