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1.
对继代6代的蚕豆的再生植株的遗传变异进行田间鉴定、籽粒形态鉴定和DNA分子标记鉴定,结果表明:在田间对株型、叶色、茎色、花色、荚色进行鉴定均没有发现变异;对籽粒形态的鉴定中仅有1%的粒色和0.5%的脐色变异;利用AFLP技术对发生农艺学性状变异的组和未发生农艺学性状变异的组进行检测,没有检测到变异;说明在继代6代时,未检测到在基因组水平上发生变异。 相似文献
2.
Summary In an attempt to incorporate variation into a uniform obligate apomict, plants of apomictic common dallisgrass, Paspalum dilatatum Poir., were regenerated from callus derived from immature inflorescences. Plants developed through both organogenesis and embryogenesis. A total of 682 regenerants were produced and more than 400 were transplanted into a field nursery and screened for somaclonal variation. Eventually 20 regenerants were selected, increased, and planted into a replicated nursery along with normal common dallisgrass. The characteristics examined were maturity date, plant height, number of racemes per inflorescence, number of spikelets per raceme, pubescence, stigma and anther color, ergot resistance, seed germination, seed set, pollen stainability, method of reproduction, and chromosome number. There were differences among the regenerants and between them and common dallisgrass for all traits except chromosome number, stigma and anther color, and ergot resistance. One of the more important regenerants had significantly higher seed set than common dallisgrass. All regenerants reproduced by aposporous apomixis but some exhibited a high degree of abortion while others had more aposporous embryo sacs per ovule than common dallisgrass. These findings demonstrate that common dallisgrass can be regenerated through tissue culture and that somaclonal variation is expressed in some of the regenerants, even though some of the altered traits are deleterious. 相似文献
3.
4.
Summary The expected improvement in grain yield if selection was made for plant characters measured between flowering and maturity was evaluated in populations of rapeseed (Brassica campestris and B. napus) grown in a droughted environment. Drought was commenced at flowering in each species and measurements were made on plants at the commencement of the drought stress, during the stress treatment and at crop maturity.Substantial genetic and phenotypic variation was observed in yield as well as the different morphophysiological determinants of yield. In B. campestris no single parameter was found to be a suitable alternative selection criterion to yield since the correlated responses in yield if selection was for another character was lower than if selection was for yield alone. By the use of a selection index however, joint selection for yield, as well as harvest index, 1000 seed weight and seeds per pod, was expected to be 20% more effective than direct selection for yield under drought. In the B. napus population direct selection for flowering time or for harvest index was predicted to result in a genetic advance in yield equal to or greater than that obtained by direct selection for yield, whereas joint selection for flowering time and yield should result in a 16% greater yield increase. Selection for increased yield in these populations grown in droughted conditions is discussed. 相似文献
5.
Genetic analyses of agronomic and seed quality traits of doubled haploid population in Brassica napus through microspore culture 总被引：1，自引：0，他引：1
Summary The results showed that the F1 genotype from the cross (Brassica napus cv. Zheshuang 758 × cv. Z-4115) had good response to embryogenesis, and their embryo yield and rate of plant regeneration reached 69.8 embryo/bud and 46.9%, respectively. Characters from the doubled haploid (DH) populations in B. napus were analyzed and it was showed that the means of each agronomic trait were between their parents, but they were nearer to the paternal in 6 agronomic traits (plant height, branch position, number of pods in the main raceme, length of pod, number of pods/plant and number of seeds/pod). The number of genes controlling each agronomic trait was analyzed based on the DH populations. The results showed that the number of genes controlling number of pods in the main raceme was the highest (15.6), and the least number of genes was involved for stem width (only 7.9). According to estimated coefficients of skewness and kurtosis of the traits tested, gene interaction was found to be absent for stem width, plant height, length of main raceme, number of primary and secondary branches, pod density in the main raceme and seed weight/plant. Complementary interaction was also observed in five agronomic traits (number of pods in the main raceme, length of pod, number of pods/plant, number of seeds/pod and 1000-seed weight). A significantly positive correlation was observed between seed yield/plant and four agronomic traits (length of main raceme, length of pod, number of pods/plant and 1000-seed weight). The experiment also showed that the erucic acid, glucosinolate, oil and protein contents of DH populations were 34.23%, 87.09 μmol/g, 44.09% and 42.67%, respectively. The numbers of genes controlling each quality trait were 7.8, 9.7, 9.4 and 8.7, respectively. Partial correlations between the seed quality traits and the agronomic characters of DH populations were analyzed. In this experiment, the partial correlations among seed quality traits were also analyzed and it was found that the oil content had a negative correlation with the other three seed quality traits. 相似文献
6.
Identification of Genes Controlling Pod Length in Spring Rapeseed, Brassica napus L., and their Utilization for Yield Improvement 总被引：6，自引：0，他引：6
Experiments were undertaken to determine the inheritance of pod length in a cross with spring rapesecd, Brassica napus, and to assess the value of pod length as a criterion of selection for high seed yield. Analyses of patterns of variation in F2; and backcross populations derived from a cross between a short-pod line TB42 and long-pod line CA553 indicated that much of the variation in pod length could be attributed to two major genes interacting in a complementary manner. Short-pods were produced when cither one or both genes were homozygous for the recessive allele. Analyses of F3 progenies of selected F2 and inbred-backcross lines derived from the same cross supported the two-gene hypothesis but also indicated that the effects of the major genes on pod length were possibly modified by genes of minor effect. Field testing of families derived from random intermating between F2, plants of the TB42 × CA553 cross showed that number of pods per plant varied independently of pod length, but seed weight per pod tended to increase with increasing pod length. As a result, families with the longest pods generally had significantly higher yields than those with short pods. It was concluded that yield improvement in B. napus could be achieved through introgression of long-pod genes into cultivars with an appropriate genetic background to ensure that selection for the long-pod character would be accompanied by an increase in seed weight per pod with little or no reduction in number of pods per plant. 相似文献
7.
Combining ability analysis and association of yield and yield components among selected cowpea lines 总被引：1，自引：0，他引：1
The study was carried out to determine combining ability and association of yield and yield components among crosses derived
from seven selected cowpea (Vigna unguiculata (L.) Walp) parents. Twenty-one hybrids were generated from diallel crosses excluding reciprocals. Hybrids along with seven
parents were studied for combining ability and phenotypic correlations for seed yield and eight yield components. The result
indicated that the general combining ability (gca) and specific combining ability (sca) were significant for most characters indicating the importance of both additive and non-additive genetic components. Additive
gene action was important for eight characters except pod number, whereas non-additive gene action was not important for nodule
number and grain yield. Parental lines IT86D-716 and IT81D-985 were found to be good general combiners for grain yield and
other traits. The most promising specific combiners for yield and yield components were from crosses including IT87D-697-2 × IT86D-716,
IT88D-867-11 × IT86D-716, IT93K-624 × IT87D-697-2, and IT87D-697-2 × IT92KD-405-1. Significant positive phenotypic correlations
were observed between seed yield with pod length (POL), number of pods per plant (PON), and number of seeds per pod (SPD).
POL, pod number per plant, SPD, and grain yield were identified as the best selection criteria that could be used in cowpea
breeding programs. 相似文献
8.
A total of 415 sorghum (Sorghum bicolor (L.) Moench) accessions representing different regions of Ethiopia, Eritrea and a group of introduced lines were evaluated
for 15 quantitative characters to determine the extent and geographical pattern of morphological variation. The extent of
variation was highly pronounced for agronomically important characters for sorghum. These characters included plant height,
days for 50% flowering, peduncle exsertion, panicle length and width, number and length of primary branches per panicle and
thousand seed weight. Significant regional variation was also observed for most of the characters. The results implied that
environmental factors such as altitude, rainfall, temperature and growing period are important in regional variation. Mean
for plant height and for days for 50% flowering showed clinal variation along the gradients of rainfall pattern and growing
period in Ethiopia. Moreover, there were significant positive correlation coefficients between most of the characters. This
included the correlation between agronomic characters of primary interest in sorghum breeding such as plant height and days
for 50% flowering and also between various characters and the altitude of the collection sites. The implications of the results
in plant breeding, germplasm collection and conservation as well as the probable sources of the wide range of variation are
discussed.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
9.
Summary
In vitro selection of salt tolerant plants of Brassica juncea L. (Indian mustard) cv. Prakash has been accomplished by screening highly morphogenic cotyledon explant cultures on high NaCl media. Out of a total of 2,620 cotyledons cultured on high salt medium, 3 survived, showed sustained growth and regenerated shoots. They were multiplied by axillary bud culture on NaCl free medium. The salt-selected shoots retained salt tolerance following 3 month of growth and multiplication on control medium. While two of these somaclones flowered and set seeds, third one grew slowly, had abnormal leaf morphology and was sterile. The seed of the two fertile plants were sown in the field to raise R1 segregating generation. Data were recorded for field, other agronomic components and oil content. The somaclonal lines, both selected salt-tolerant and non-selected, showed tremendous amount of variation for all the characters studied. One of the two tolerant somaclones invariably showed reduced height, longer reproductive phase and higher 1000 seed weight. Based on the agronomic performance of R1 plants of these somaclones, some plants were selected and their progeny were evaluated for agronomic performance under standard field conditions and salt-tolerance in the greenhouse using sand pot culture method. Most of the lines bred true for their specific characteristics. In the greenhouse, selected salt-tolerant somaclones (SR-2 and SR-3) performed better for plant growth, yield and other agronomic traits at higher salt treatments, indicating thereby that salt-tolerance trait selected in vitro was expressed in the whole plants and is genetically stable and transmitted onto the progeny. The two tolerant lines, however, differed in their salt-tolerance during vegetative and reproductive phases as indicated by their salt-tolerance and stress susceptibility indices. The mechanism of salt-tolerance is not clear and needs to be further investigated. 相似文献
10.
Summary Diploid Hordeum bulbosum L. (2n=2x=14), collected for the first time in south-west Spain, is described. One hundred and ten plants from the original seed were grown to maturity to determine the type and extent of phenotypic variation within the population. Cytological study verified that all the plants were diploids. The plants proved to be variable for traits such as growth type, tiller number, culm and spike length, flag leaf length and width and bulb characteristic and size. The variation in the diploids was found to be greater than previously reported. The plants found in elevations 150–250 m do show differently to other groups with respect to several morphological characters.Contribution No. 727. 相似文献
11.
Pigeonpea [Cajanus cajan (L.) Millsp.] is an important legume crop in the semi-arid tropics, and pod fly [Melanagromyza obtusa (Malloch)] is an important emerging constraint to increase the production and productivity of this crop under subsistence
farming conditions. Host plant resistance can be used as an important tool for the management of this pest. Therefore, a set
of ten pigeonpea genotypes from a diverse array of plant growth types and maturity groups including two appropriate commercial
checks, was evaluated for resistance to pod fly under field conditions, and characterized for physico-chemical pod traits.
The non-determinate type GP 75 (extra early maturing) and GP 118 (early maturing), and determinate type GP 233 (extra early
maturing) and GP 253 (early maturing) genotypes had significantly lower pod and seed damage as compared to determinate (Prabhat) and non-determinate (Manak) early maturing checks, suggesting that resistance to pod fly is not linked to plant growth type and maturity period of the
genotype in pigeonpea. Pod wall thickness, trichome density, reducing and non-reducing sugars, total phenols, tannins, and
crude fiber were found to be negatively associated (r = −0.83** to −0.97**), while total protein positively associated (r = 0.88** to 0.97**) with pod fly infestation. Therefore, these traits particularly total phenols, tannins, crude fiber, trichome
density, and pod wall thickness, can be used as physico-chemical markers to identify pigeonpea genotypes with resistance to
M. obtusa, and use in pod fly resistant breeding program in pigeonpea. 相似文献
12.
Summary The efficiency of indirect selection for seed yield was compared with direct selection for yield per se in chickpea. A total of 2500 single F2 plants, derived from 50 crosses with 50 plants from each cross, were divided into five sub-populations (SP1 to SP5) of 500 plants each by including 10 plants from each of the 50 crosses. The five sub-populations were advanced upto F6 by exercising 10% selection intensity for four successive generations for number of pods per plant in SP1, number of seeds per pod in SP2, seed weight in SP3, seed yield in SP4 and random selection in SP5. The efficiency of direct and indirect selection for yield was evaluated by comparing groups of 50 F6 lines from each sub-population. SP1 and SP3 F6 lines showed higher mean grain yield than the other three methods. SP1 and SP3 were found to be almost equally efficient in developing F6 lines which were significantly superior to the check. This suggests that indirect selection for yield via pod number and seed weight is more efficient than direct selection for yield. 相似文献
13.
Summary Three thousand two hundred and sixty-seven kabuli chickpea (Cicer arietinum L.) germplasm accessions were grown during the spring season of 1980 at Tel Hadya, the main research station of ICARDA, Syria to determine the components of seed yield. Observations were recorded on seed yield and 14 other characters. Correlation and path coefficient analyses were done to find out associations among characters and to assess the direct and indirect contribution of each character to seed yield.Large variation was observed for all the characters studied except days to flowering, days to maturity and protein content. Correlation and path coefficient analyses showed that biological yield and harvest index were the major direct contributors to seed yield. The 100-seed weight, plant height, days to flowering and maturity, canopy width, and protein content contributed to seed yield mainly through indirect effect via biological yield and harvest index. The 100-seed weight and seed yield were major contributors to biological yield. Major contributor to protein content was days to maturity. Results indicated that selection for high biological yield and harvest index would lead to high seed yield; and selection for large seed size would lead to high biological yield. Therefore, these characters should receive the highest priority in selecting high yielding plants in chickpea breeding. 相似文献
14.
对122份国外普通菜豆资源的熟性、生育日数、生长习性、出土子叶色、叶形、花旗瓣色、花翼瓣色、株高、株型、主茎节数、单株分枝数、结荚习性、单株荚数、每果节荚数、荚色、荚形、荚面、荚长、荚宽、单荚粒数、粒形、种皮光泽、种皮斑纹、粒色、百粒重、单株产量、小区产量15个质量性状和12个数量性状进行聚类分析和主成分分析。结果表明,122份国外普通菜豆资源聚为四类,其中来自葡萄牙的91号资源单独为一类。主成分分析结果表明,26个性状提取了8个主成分,累计贡献率为74.37%,包括颜色因子、百粒重因子、产量因子、形态因子等主要因子。该研究旨在充分挖掘国外菜豆种质资源特性,为资源利用提供依据。 相似文献
15.
A.H. Marshall T.P.T. Michaelson-Yeates M.T. Abberton A. Williams H.G. Powell 《Euphytica》2002,126(2):195-201
Interspecific hybridisation with Trifolium nigrescens Viv. is a possible strategy to improve the reproductive potential of white clover (Trifolium repens L.). Following the development of a fertile F1 hybrid, three generations of backcrossing have been carried out usingT. repens as the recurrent parent. Vegetative characteristics, stolon growth and seed yield components of the backcross (BC) 2 and
3 generations, as well as the parental species were measured on spaced plants grown in the field. Leaf size and plant spread
of the BC2 and BC3 generations were less than T. repens but there was no difference in plant fresh weight. Numbers of inflorescences per plant and florets per inflorescence of the
backcrosses were greater than T. repens however this was not reflected indifferences in seed yield per plant asT. repens had more seeds per floret and per plant than the backcrosses. Differences in stolon length, the proportion of flowering nodes
and the pattern of axillary bud development were observed between T. repens and the backcrosses. Significant variation among the BC 3 generation for vegetative and reproductive traits was observed.
Individual plants among the BC 3 generation were identified that combine high forage yield, substantial inflorescence production
and good fertility, and these will form the basis of further selection.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
16.
Summary Employing in vitro culture of ovaries, ovules and embryos, interspecific hybrids have been obtained amongst two important oilseed crops, Brassica napus x B. juncea and their reciprocal. The test-tube hybrid plants have been transferred to the field, and reared to maturity. The F1 seeds obtained from the hybrid ovaries showed normal germination, and the hybrid plants exhibited a range of variation of characters. 相似文献
17.
豇豆种质资源农艺性状的相关性、主成分及聚类分析 总被引：2，自引：1，他引：1
为给豇豆育种中品种资源的合理利用提供依据,对41份豇豆品种资源15项主要农艺性状进行相关性、主成分和聚类分析。结果表明,枯萎病发生程度的变异系数最大,与豇豆产量关系密切的单荚重和单株嫩荚数2个农艺性状,与株型、嫩荚长、单株花序数和单荚种子粒数都呈现显著正相关,单株嫩荚数与开花期、叶宽和单株分枝数呈现显著负相关。15个主要农艺性状可以归纳为5个主成分,第1主成分包括株型、初花节位、嫩荚长、单荚重、单荚种子粒数、单株花序数、单株嫩荚数和单株分枝数;第2主成分包括开花期、叶长和叶宽;第3主成分包括种皮颜色和嫩荚宽;第4主成分包括嫩荚颜色;第5主成分包括枯萎病发生程度。41份豇豆种质资源在遗传距离为25处分为2大类,在遗传距离为15处分为Ⅰ、Ⅱ、Ⅲ类,其中第Ⅰ类的品种优势明显,具有较好的应用前景。 相似文献
18.
Summary A chromosome interchange in soybean (Glycine max (L.) Merr.) was studied agronomically and genetically, and comparisons of seed or abortion position within the pod were related to chromosome structure. Comparisons were among plants heterozygous for a chromosome interchange (N/T), plants homozygous for the interchange (T/T), and homozygous normal-chromosome plants (N/N). The latter two genotypes were male fertile and female fertile. Heterozygous interchange plants, which are about 50% pollen sterile and ovule sterile, are typical of a large number of plants that have equally frequent alternate and adjacent chromosome segregation. Yield, lodging, plant height, and seed oil and protein percentages among all three genotypes were similar even though significant differences existed for seed weight, seed number, and pod number per plant. Seed abortions were more frequent in the basal position of the pod than in either the middle or apical positions in N/N and T/T genotypes. Ovule abortions in N/T plants were equally frequent among all positions both in two- and three-ovule pods. The middle seed in a three-ovule pod was heavier than the basal or apical seed among all three genotypes.Joint contribution: USDA ARS, and Journal Paper No. J-11300 of the Iowa Agriculture and Home Economics Experiment Station, Ames, Iowa 50011, USA, Project 2471.USDA ARS, Department of Agronomy and Genetics, Iowa State University, Ames, Iowa 50011, USA.Department of Agronomy, Iowa State University, Ames, Iowa 50001, USA. 相似文献
19.
The pentaploid hybrid of Lolium multiflorum and Festuca arundinacea (2n = 5x = 35) combines the high growth rate of L. multiforum with the drought resistance and freezing-tolerance of F. arundinacea. Unfortunately, it also displays the deleterious traits associated with Festuca, namely those associated with high leaf fibre content giving rise to poor palatability and digestibility. To access different
combinations of these characters, anther cultures were initiated and regenerated into single embryo derived plants. The anther
culture method was very productive since out of a total of 2349 androgenic plants derived from the same parent plant, 57%
were green plantlets, although only 507 (22%) subsequently established into plants following transfer to soil. Chromosome
counts of randomly selected lines showed that plants with euploid chromosome numbers (14, 21, and 28) would appear to have
selective advantage during regeneration. There was wide variation between mature androgenic plants grown under field conditions
in plant height, leaf length, leaf width, tiller number and herbage dry matter. The variation between genotypes in response
to drought stress was assessed by placing replicate clones under rain-out shelters or under irrigated control conditions in
the field. Herbage dry matter under drought was higher in a number of androgenic lines than either parents, but not higher
than the pentaploid hybrid. Androgenesis was shown to be a highly effective procedure to expose diverse phenotypic variation
all derived from the same Lolium × Festuca hybrid genotype.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
20.
V. Orbović M. Ćalović Z. Viloria B. Nielsen F. G. Gmitter Jr. W. S. Castle J. W. Grosser 《Euphytica》2008,161(3):329-335
Five populations of lemon plants [Citrus limon (L.) Burm] obtained from undeveloped ovules through different tissue culture procedures were examined for the presence of
somaclonal and irradiation-induced genetic variation. Tested groups were: (1) nucellar seedlings; (2) organogenic, regenerated
via adventitious buds from nucellar seedling internodes; (3) embryogenic population, regenerated from non-irradiated nucellar
callus via somatic embryogenesis; (4) embryogenic population, regenerated from irradiated nucellar callus via somatic embryogenesis;
and (5) protoplast-derived, regenerated via somatic embryogenesis. Genomic DNA samples from 360 plants (72 from each group)
were screened for polymorphism among RAPD fingerprints amplified by 10 decamer primers. Among all tested plants, genetic variation
was detected only within the group of plants recovered from irradiated embryogenic calli. Out of 72 plants from that group,
three had RAPD fingerprints different from the rest of the population, and fourth plant was found to be cytochimeric, consisting
of diploid and tetraploid cells as revealed by flow cytometry. In all other populations of regenerated plants, we did not
come across any plants with changed ploidy level. 相似文献