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1.
The consumption of products made from Tartary buckwheat (Fagopyrum tataricum (L.) Gaertn.) has increased in recent years in Japan. Increased consumer demand has led to recognition of the need for early varieties of this crop with high and stable yields. In order to accomplish this, more information is needed on the genetic mechanisms affecting earliness and yield. We conducted genetic analysis of 3 agronomic traits (days to flowering, plant height and total seed weight per plant) to segregate F2 and F3 populations derived from a cross between Tartary buckwheat cultivars ‘Hokuriku No. 4’ and ‘Ishisoba’. Broad-sense heritability estimates for days to flowering, plant height and total seed weight were 0.70, 0.62 and 0.75, respectively, in F3 population. Narrow-sense heritability for total seed weight (0.51) was highest, followed by heritability for days to flowering (0.37), with heritability for plant height (0.26) lowest. Later flowering was associated with increased plant height and higher yields. From the F4 generation, we identified twelve candidate plants with earlier maturity and reduced plant height compared to ‘Hokuriku No. 4’, but almost the same total seed weight. These results suggest that hybridization breeding using the single seed descent (SSD) method is an effective approach for improving agronomic characteristics of Tartary buckwheat.  相似文献   

2.
In a screening of about 500 lines of Tartary buckwheat, we identified lines that contained no detectable rutinosidase isozymes using an in-gel detection assay. We confirmed that seeds of these individuals had only a trace level of in-vitro rutinosidase activity. To investigate the heritability of the trace-rutinosidase characteristic, we analyzed the progeny of crosses between rutinosidase trace-lines, ‘f3g-162’, and the ‘Hokkai T8’. The F2 progeny clearly divided into two groups: those with rutinosidase activity under 1.5 nkat/g seed (trace-rutinosidase) and those with activity over 400 nkat/g seed (normal rutinosidase). The segregation pattern of this trait in F2 progeny exhibited 1 : 3 ratio (trace-rutinosidase : normal rutinosidase), suggesting that the trace-rutinosidase trait is conferred by a single recessive gene; rutinosidase-trace A (rutA). In addition, sensory panelists evaluated the bitterness of flour from trace-rutinosidase individuals and did not detect bitterness, whereas flour from normal rutinosidase individuals was found to have strong bitterness. Although at least three bitter compounds have been reported in Tartary buckwheat seeds, our present findings indicate that rutin hydrolysis is the major contributing factor to bitterness. In addition, the trace-rutinosidase line identified here, ‘f3g-162’, is a promising material for generating a non-bitter Tartary buckwheat variety.  相似文献   

3.
荞麦适应性广、种质资源丰富,是一种药食同源作物,其籽实具有很高的营养价值。荞麦籽粒由胚、胚乳和外壳构成,外壳富含木质素、纤维素和糖,导致脱壳困难,这一性状严重制约着荞麦加工产业的发展,因此培育易脱壳种质资源是荞麦育种的主要目标之一。荞麦种壳的形成和开裂受遗传和环境共同调控,为了充分了解影响荞麦脱壳的因素,本研究归纳了不同荞麦种壳的组成及细胞排列方式;总结了酶在种子壳裂发生过程中的作用及蜡质角质层在种子外壳脱落过程中的功能;分析了转录因子对壳发育的调控。本研究同时指出了薄壳和厚壳荞麦种壳发育和裂壳性状的主要差异及其关键候选调控基因,为脱壳关键调控基因克隆和高效分子设计育种提供重要的理论依据。  相似文献   

4.
In a self-fertilised crop like lentil, the identification of transgressive segregants for economically important trait such as seed yield is an important aspect of any practical breeding programme. The prediction of expected transgressive segregants in F1 generation obtained as a ratio of additive genic effect [d] and additive variance (D) i.e. [d]/√D was studied in 28 crosses of lentil generated in a diallel fashion involving four parents each of macrosperma (exotic) and microsperma (Indian) types, respectively, resulting in three hybridization groups. The seed material advanced to F2, F3 and F4 generations through single seed descent method was evaluated to determine the observed transgressive segregants for seed yield/plant. The observed frequency of crosses showing more than 20% transgressive segregants in F2 to F4 generations were exhibited in 9(32%) crosses, of which 7(77%) crosses were of macrosperma × microsperma type. Genotypes Precoz and HPL-5 of the exotic group (macrosperma) produced maximum number of transgressive segregants with the genotypes L-259, L-4145 and PL-406 of the Indian origin (microsperma). Goodness of fit (non-significant χ2 value) in F2 generation was observed for 19(68%) crosses of the total genepool, out of which 9(56%) crosses each in F3 and F4 generation belonged to the macrosperma × microsperma group, depicting it as the gene pool of paramount importance to obtain maximum transgressive segregants, therefore establishing the efficacy of the method used.  相似文献   

5.
Hot water treatment was applied to Tartary buckwheat (var. ‘Hokkai T8’) for emasculation. Apical clusters of flower buds were soaked in a constant temperature water bath (42–44°C) in the afternoon and then the flowers which opened in the next morning were used for the investigation of self-fertilization and the artificial pollination. Hand pollination was carried out by rubbing the anthers taken from the male parent (var. ‘Hokkai T10’) to the stigma of the flowers treated by hot water. The seed set by self-fertilization was almost 0% when treated at 42°C for 8 min or more, at 43°C for 5 min or more and at 44°C for 3 min or more. With artificial pollination, the best performance was obtained when treated at 44°C for 3 min, in which the seed set was 55.1% and the matured seed was obtained 37.7% of the hand-pollinated flowers. Nine out of 26 progeny seedlings emerged and the cotyledonal color of them were all reddish green, probably indicating the hybrid of ‘Hokkai T8’ and ‘Hokkai T10’. The hybridization was reconfirmed by the segregation in F2. The hot water treatment at 44°C for 3 min was available to other seven varieties. From 24.5% to 100% of the hand-pollinated flowers set mature seeds though only one self-fertilized seed remained without artificial pollinations. This hot water treatment must be practically useful in hybridization breeding of Tartary buckwheat.  相似文献   

6.
The most important breeding objectives in crop improvement are improving grain yield, grain quality, and resistances to various biotic and abiotic stresses. The objectives of our study were to compare two crossing and four selection schemes for grain yield, yield traits, and slow rusting resistance to leaf rust (Puccinia recondita) based on additive genes in wheat (Triticum aestivum), and to identify the most efficient crossing and selection methodologies in terms of genetic gains and cost efficiency. Segregating populations were derived from 18 simple crosses and the same number of top (three-way) crosses. Half of the crosses were derived from Yecora 70 and the other half from Veery #10 as the common leaf rust susceptible parents. The four selection schemes were: pedigree, modified bulk (F2 and F1-top as pedigree, selected lines in F3, F4, F2-top, F3-top as bulk; and pedigree in F5 and F4-top populations), selected bulk (selected plants in F2, F3, F4, F1-top, F2-top and F3-top as bulk; and pedigree in F5 and F4-top populations), and nonselected bulk (bulk in F2, F3, F4, F1-top, F2-top and F3-top; and pedigree in F5 and F4-top populations). A total of 320 progeny lines, parents and checks were tested for grain yield, other agronomic traits and leaf rust resistance during the 1992/93 and 1993/94 seasons in Ciudad Obregon (Sonora State, Mexico) which represents a typical high yielding irrigated site. The influence of the type of cross and the selection scheme on the mean grain yield and other traits of the progenies was minimal. The selection of parents was the most important feature in imparting yield potential and other favourable agronomic traits. Moreover, the highest yielding lines were distributed equally. Progeny lines derived from Veery #10 crosses had significantly higher mean grain yield compared to those derived from the Yecora 70 crosses. Furthermore, a large proportion of the highest yielding lines also originated from Veery #10 crosses. Mean leaf rust severity of the top cross progenies was lower than that of the simple cross progenies possibly because two parents contributed resistance to top cross progenies. Mean leaf rust severity of the nonselected bulk derivatives was twice that of lines derived from the other three schemes. Selected bulk appears to be the most attractive selection scheme in terms of genetic gains and cost efficiency. This revised version was published online in August 2006 with corrections to the Cover Date.  相似文献   

7.
Suitable breeding procedure for crop improvement mainly depends on the type and relative amount of genetic components and presence of non‐allelic interactions. Therefore, the study was carried out during three successive rabi seasons 2013‐14, 2014‐15 and 2015‐16 in mid hill zone of North‐western Himalayas, India with objective to estimate the main genetic effects including digenic non‐allelic interactions controlling horticultural traits in cauliflower. The generation mean analysis was carried out on six generations (P1, P2, F1, F2, B1 and B2) of six crosses involving four diverse parents of cauliflower. The results obtained revealed that the nature and magnitude of gene effects differed in different crosses and showed importance of duplicate epistasis in the inheritance of curd diameter and curd size index, whose effect can be wiped out by following sophisticated selection procedure such as reciprocal recurrent selection and/or biparental mating in early segregating generation. Complementary type of epistasis was recorded in most of the cross combinations for the important yield traits, which indicates the importance of heterosis breeding for the development of high yielding varieties.  相似文献   

8.
Z. Luthar    S. Rogl    B. Kump    B. Javornik 《Plant Breeding》2008,127(3):322-324
The inheritance of buckwheat (Fagopyrum esculentum Moench) seed storage proteins was investigated by control crosses between accessions containing different SDS‐PAGE protein patterns in the range of 38–48 kDa. Analysis of segregation of individual F1 and F2 seeds obtained by 17 crosses showed segregation of eight electrophoretic bands, from which 12‐banding variants were inferred. Two variants contained one band, nine contained two bands and one variant contained three bands and behaved as a single co‐dominant unit. The segregation of banding variants fits the expected ratios and thus supports the hypothesis of single Mendelian gene inheritance and that alleles are co‐dominant. The results therefore suggest that the genes controlling globulin subunits are tightly linked and inherited as a single locus. The locus was designated Glob‐1 and the twelve segregated protein variants as alleles a‐l. This is the first buckwheat globulin locus identified with multiple alleles, phenotypically expressed as groups of protein bands and thus applicable as a functional marker in buckwheat genomic studies.  相似文献   

9.
J. Sneep 《Euphytica》1977,26(1):27-30
Summary If a breeder is to apply selection to a cross-population of a self-fertilizing crop and wishes to maximize his chances of finding a productive genotype, he will have to introduce yield tests in the F3 lines. Should he not do so because of his intention to work on many populations simultaneously, his tests would be considerably less accurate and the finding of a favourable combination more or less a matter of mere chance.Bulk breeding will result in genetic drift or numbers of plants too large to manage, or in a combination of both.Application of the Single Seed Descent for quantitative characteristics causes such a genetic drift, that the method is not to be recommended.Multiple crosses (double-crosses) to improve quantitative characteristics require populations of a size, that cannot be realized and/or selected. This type of crosses is more suited for cases in which qualitative characteristics form the breeding goals and when it is impossible to obtain the favourable combination using only two varieties.Genic recessive male sterility may be a means to raise large progenies. In the F3 it confuses the issue of yield of fruits or seeds, which is highly vulnerable in any case. In the F2 its significance for finding the proper recombinant is very low.  相似文献   

10.
Wild Cicer species are considered to be more resistant for biotic and abiotic stresses than that of the cultivated chickpea (Cicer arietinum L.). Alien genes conferring resistance for biotic and abiotic stresses can be transferred from wild Cicer species to the cultivated chickpea but success in interspecific hybridizations has already been achieved with only two wild Cicer species. The current study was undertaken to compare fruitful heterosis in F2 and F3 for yield and yield criteria and to identify transgressive segregation in F2 and F3 in reciprocal interspecific crosses between C. arietinum and C. reticulatum Ladiz. We define fruitful heterosis as a useful parameter that can be used instead of residual heterosis. Considerable fruitful heterosis in F2 and F3 was found for number of seeds, pods per plant, biological yield, and seed yield. Maximum values of most of the characteristics in F2 and F3 were higher than that of the best parent indicating that superior progeny could be selected for yield from transgressive segregation. Progeny selection should be based on number of seeds, pods per plant, and biological yield since these characteristics had the highest direct effect on seed yield. The narrow sense heritability was found to be the highest for 100-seed weight. It was suggested that the cultivated chickpea could be used as female parent in interspecific hybridization to increase yield and yield criteria since progeny in F2 and F3 had better performance when it was used as female. In conclusion, interspecific hybridization of wild and cultivated chickpea can be used to improve yield and yield components and resistance to biotic and abiotic stresses as well.  相似文献   

11.
H. G. Nass 《Euphytica》1979,28(1):161-167
Summary Three methods were evaluated as potential aids in identifying superior crosses early in the breeding program: (1) F1 yield, (2) F2 yield, and (3) midparental yield. Two sets of spring wheat (Triticum aestivum L. em. Thell.) crosses and parents were evaluated in replicated single row plots in F1 and in replicated multi-row plots in F2 over a period of five years. On the basis of F1 yields, two of the highest yielding and two of the lowest yielding crosses in each set were chosen for a more detailed selection study in subsequent generations.In Set 1, random F2 head selections for each of the selected four crosses were evaluated in 3-row yield plots in F4. In Set 2, F2 plant selections were made on the basis of head weight and the highest yielding 10% evaluated for yield in F4.Lines of crosses identified as high yielding in F1 had significantly greater mean yields in F4 than those of crosses that were low yielding in F1. The high yielding crosses had three to four times as many lines yielding in the top 10% in F4 than did the low yielding crosses.Correlations for yield were obtained between F1 and F2 in different years, F2 and midparents in the same year, lower or no correlations between F1 and midparents in the same year, and no correlations between F1 and midparent and F2 and midparent in different years. It is suggested that larger plot sizes rather than single rows be used to evaluate parents.Midparental yield, F1 yield and F2 yield tests are recommended as a progressive set of screening tests for a given set of crosses to effectively maintain the superior crosses in the breeding program.  相似文献   

12.
V. K. Gupta  S. Gudu 《Euphytica》1991,52(1):33-38
Summary Phylogenetic relations among the three species in grain amaranth need investigation to provide information for breeding experiments germplasm conservation efforts, and decision on evolutionary patterns in the grain types. Hybrid development from crosses between species was studied to find out genetic relationship between them. Interspecific crosses were made among Amaranthus hypochondriacus, A. caudatus and A. cruentus in the glasshouse. The F1 plants were relatively easy to obtain but had low pollen fertility (10.3–15.1%) and low seed set. A few of these hybrids did not produce seeds. Only a few F1 seeds obtained in crosses between A. cruentus and A. caudatus. All the F1 plants from these crosses died at the seedling stage. Crosses between A. cruentus and A. hypochondriacus produced few seeds. Most of the F1 plants obtained from the seeds died at the seedling stage with only four plants growing to maturity but were sterile. Based on hybrid development, it was suggested that A. hypochondriacus and A. caudatus were genetically closer than the other two combinations of species studied. A. cruentus seemed to be genetically closer to A. hypochondriacus than it was to A. caudatus.Research was supported by Grand No. AMA-KE-4-83-22. (CRG GRANT) from the National Academy of Science, U.S.A.  相似文献   

13.
Soybean seed averages about 40% protein and is a dominant source of protein in animals and human foods. Increasing protein in soybeans is a goal in soybean breeding programs. Initial selection for protein among progeny from breeding populations is often based on non-destructive Near Infrared Reflectance (NIR) spectroscopy analysis of a 5 g or more seed sample in the F3 or later generations. NIR spectroscopy analysis for protein on single F2 seed would allow selection at the earliest possible time and improve selection efficiency for protein content; however this practice has not been evaluated. The objective of this study was to test effectiveness of NIR spectroscopy analysis of single F2 seeds to select for increased protein content from two populations developed from high and average protein content parents. F2 seeds from a single F1 plant of each population showed a normal distribution with transgressive segregation for protein concentration. In both populations, F3 seeds produced from plants from single F2 seeds with either low or high protein content were analyzed for protein by NIR spectroscopy. Protein means and ranges of F3 seed selected from high protein F2 seeds were higher in protein than F3 seed from low protein F2 seeds which produced low means and ranges in protein content. This shows that analysis of single F2 seed for protein content using NIR spectroscopy was effective in selecting for increased protein in the F3 generation. Analysis of single F2 seeds from breeding populations will improve breeding efficiency for protein in soybean breeding programs.  相似文献   

14.
Tomatoes are the most important vegetable, globally as well as in Germany. Outdoor tomato production is seriously impaired due to increasing infections with evolving late blight (Phytophthora infestans) populations. Within organic agriculture, research is being conducted to develop regionally adapted and open pollinated cultivars of outdoor tomatoes with late blight field resistance. In the present experiment, three crosses, including wild, cocktail, and beefsteak tomatoes, were selected for field resistance against late blight in F2 at one location per cross. The comparison of positive and negative selection in F3 revealed the selection of single F2 plants to be efficient in all three crosses. F2 selection has proved to be a robust and efficient tool for breeding programs. The correlated response to selection in other traits, including yield, fruit weight, days to maturity, harvest period, and plant height, depended on the cross. It was evident that selection for desired traits combined with field resistance against late blight is promising, even in wide crosses. The most undesired attribute of wild tomatoes is the formation of shoots on leaves and in inflorescences. No correlation was observed between field resistance and shoot formation, allowing the selection of genotypes with improved field resistance and yield, but without morphological disadvantages.  相似文献   

15.
F. G. H. Lupton 《Euphytica》1961,10(2):209-224
Genetic analysis of a diallel series of crosses involving six varieties of winter wheat is described. Predictions on the potentialities of the parental combinations involved are made, based on the analysis of yielding capacity and its principal components (grain weight, grains per ear and ears per plant) obtained in F1 and F2 trials.The validity of these predictions is estimated by comparison with estimates of mean yield and variance in yielding capacity obtained from trials, in F3 and F4, of randomly selected F2 plant progenies from each of the component crosses. The results obtained are discussed in relation to practical problems of crop prediction, and a system is outlined combining the analysis of diallel series of crosses in F1 and F2 with trials, in F3 and F4, of F2 plant progenies from selected crosses.  相似文献   

16.
Hybrid dwarfness is the phenomenon that after crossing of normal genotypes dwarfs are obtained in the F1 or not before the F2-generation. The literature on hybrid dwarfness in wheat is critically discussed. A new hypothesis on its genetic basis is given, taking McMillan's (1937) as a starting point. Dwarfness is assumed to be determined by the additive interaction of three genes D 1, D 2 and D 3, differing in dominance relations and in quantitative contribution to the dwarf phenotype.Three dwarf types are described. Type 1-dwarfs are dwarf during their whole life cycle and normally do not produce seeds. Type 2-dwarfs start as normal seedlings, become dwarfs while tillering and die dwarfs; some produce seeds, others do not. Type 3-dwarfs emerge as normal seedlings, become dwarfs during the tillering stage, but after some time they start to shoot and develop into nearly or even completely normal plants; in the F2 the proportion of dwarfs decreases during the growing season. The occurrence and genetic basis of the three dwarf types is discussed.On the basis of their genotype 315 varieties and lines are divided into six genotypeclasses. Over 1000 intra- and inter-class crosses were made and F1, F2, F3, and BC studied. Also some triple crosses and crosses with pure breeding dwarfs were investigated. In general the results obtained fit the hypothesis. Unstable ratios involving type 3-dwarfs are discussed separately.Linkage of the dwarf gene D 2 and the necrosis gene Ne 2 (both on chromosome 2B (XIII) was apparent from F2-data and from results of a triple cross in which both forms of hybrid weakness occurred. Crossing-over between D 2 and Ne 2 is calculated to be 34%.Methods are outlined to use hybrid dwarfness in a wheat breeding programme. The possible incompleteness of the three-gene hypothesis and the variability of dwarfness are discussed and finally some suggestions are made for future research.  相似文献   

17.
Summary F5 seeds from six highly heterotic F1 hybrids were produced to determine whether the superior performance of F1 hyrids could be fixed in pure-line derivatives of pea (Pisum sativum L.). For each cross, 24–31 F5 lines derived from single seed descent were compared with F1 hybrids and their parents in two environments. The F1 hybrids out-yielded the best parent by up to 11%. All crosses produced F5 lines which were as high in yield as the F1 hybrids indicating that pure-line derivatives equivalent in yield to the heterotic F1 hybrid could be developed by conventional breeding. Heterosis of the F1 hybrids over the best commercial cultivar was thus a useful indicator of the future performance of the pure-line derivatives. These results indicate that overdominance was not an important component of heterosis in peas.  相似文献   

18.
Successful identification of a desirable segregant depends partly on the parents chosen to make the crosses. This experiment was conducted to compare performance and genetic variability for seed yield, yield components, agronomic traits and harvest index of lines derived from low- and high-yielding flax (Linum usitatissimum L.) crosses, and to identify important yield components for flax seed yield improvement. The lines chosen as high yielding parents for this experiment were‘Linott’and 'Summit; and the low yielding parents were‘Grant’and Ci2395. The high-yielding lines produced significantly more seeds per boll and had a higher harvest index than the low-yielding lines. Evaluation of 161 F2:6 lines from four crosses among these lines showed that the greatest genetic variability, highest cross average, and highest F6 line seed yield occurred in the low x high cross,‘Grant’x‘Linott’. All low X high crosses exhibited higher genetic variances for seed yield than the high x high crosses. The high x high cross 'Summit’x‘Linott’had low genetic variance for seed yield. Number of bolls per area was determined by linear regression, path coefficient analysis, and stepwise multiple regression analysis to be the most important component of seed yield. This study showed that hybridization of low and high-yielding flax lines may be useful to increase genetic variability and obtain high-yielding flax lines.  相似文献   

19.
Interspecific hybridization offers potential to improve the hydroxy fatty acid (HFA) content of lesquerella. Lesquerella fendleri is currently being developed for cultivation as a potential new industrial oilseed crop because of its seed productivity. However, it has lower HFA content compared to L. pallida and L. lindheimeri. The objectives of this research were to improve the HFA oil content of L. fenderi through interspecific hybridization and to characterize hybrids and successive generations for seed oil fatty acid profile, fertility, seed set and other morphological traits. In this work, three species were successfully hybridized, self-pollinated, and backcrossed. Ovule culture was used in some cases to produce progeny where interspecific hybrids did not produce viable embryos. The traits measured were petal length, ovules per silique, seeds per silique, and weight of 1000 seed. Patterns of leaf trichomes were used to distinguish between parents and hybrids. Seed per silique indicated that autofertility occurred in L. pallida but not in the other two species. HFA oil content of L. fendleri seed were 50.5% compared to 80 and 84% for L. pallida and L. lindheimeri, respectively. The HFA oil content of the hybrids ranged from 57 to 70% in A2 and A3 generations, and the range of values depended on the parents used in the crosses. These measurements will help predict the value of different interspecific crosses for breeding. Segregation for various yield related traits should allow selection for favorable improvements in the HFA trait and in seed yield.  相似文献   

20.
Fifty-five mungbean lines were evaluated for days to maturity and grain yield per plant. This material showed considerable range of variability for the target traits. Eight genetically diverse parents were selected and used for a full diallel set of crosses to study the mode of inheritance for earliness related parameters (days to flowering, days to maturity and length of reproductive phase) during summer 2005. The F1 generation of these crosses was sown during the spring of 2006 and the selfed seeds were used to raise the F2 generation during kharif season. The data recorded from two generations were subjected to genetic analysis. The formal ANOVA showed the significance of both additive and dominance effects for all the traits in both generations. Significance of D, H1 and H2 components also confirmed the contribution of both additive and dominance effects in controlling the inheritance of these traits. The estimates of narrow sense heritability were low to moderate except higher estimates for days to maturity in F2 generation, while the broad sense heritability estimates were relatively higher. Seasonal and environmental effects were also found to be significant. In view of the complex nature of gene action for earliness, it is suggested that breeders should look for transgressive recombinants of earliness and other desirable attributes in later segregating generations to gain higher genetic advance. The variety NM92 was found to be the best source of earliness in mungbean breeding.  相似文献   

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