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101.
Optimization of DH-line based recurrent selection procedures in maize under a restricted annual loss of genetic variance 总被引:1,自引:0,他引:1
Doubled haploid (DH) lines are increasingly being used in commercial hybrid maize (Zea mays L.) breeding. They allow for various quantitative genetic and logistic advantages provided that they are implemented in efficient
and optimally allocated breeding procedures. In the present study, a new software was applied to optimize two recurrent selection
(RS) schemes for hybrid maize breeding based on DH lines under a restricted annual budget and an upper limit for the relative
annual loss of genetic variance. This software maximizes the expected gain from selection in general combining ability by
means of quantitative genetic model calculations. Optimization results are compared for one, two, and three stages of testcross
selection under different assumptions regarding the evaluation of lines per se and the annual budget. Results show that the
optimum allocation of technical and budget resources to the individual steps of an RS program and the efficiency of alternative
RS procedures are decisively determined by the number of selection stages. Under standard assumptions, one-stage selection
was superior to two- and three-stage selection. Thus, shortening the length of an RS scheme considerably increases its efficiency.
By intercrossing a reduced number of selected lines for starting a new RS cycle, the short-term response to selection may
be increased, but the population size and, thus, the selection limits in the long run are diminished. Therefore, fair comparisons
of alternative RS procedures require to define the intended time span for maximizing the genetic gain from RS and to restrict
the relative annual loss of genetic variance accordingly. 相似文献
102.
Jian Gu Kun Liu Shaoxiang Li Yuxian Tian Hexian Yang Mujun Yang 《Frontiers of Agriculture in China》2008,2(4):391-395
The wheat × maize system is one of the most effective ways to produce haploids in wheat. Whether and how it could be successfully
applied in practical breeding mostly depends upon the efficiency of haploid embryo production. To perfect the protocols of
haploid embryo induction, the efficiency of haploid embryo production between in vitro culture of cut plant and intact plant growth for hybrid spikes with two F1 wheat hybrids and two maize varieties was compared. Effects of different cutting plant times and formulas of nutrient solutions
for cut plant culture on haploid embryo formation were also studied. Results indicated that the embryo rate of in vitro culture was 3.29 times that of intact plant growth, with the figures of 31.6% vs 9.6%, respectively. The optimal time for cut plant culture was 24 h after pollination. Formulas of nutrient solutions significantly
affected the efficiency of haploid embryo induction. With an embryo rate of 0–35.5%, adding calcium phosphate in the culture
solution at 3 g·L−1 could raise the caryopsis and embryo rates. According to this study, the best medium for cut plant culture was: 100 mg·L−1 2,4-D+ 40 g·L−1 sucrose + 10 mg·L−1 silver nitrate + 8 mL·L−1 sulfurous acid + 3 g·L−1 calcium phosphate, with which a caryopsis rate of 95% and an embryo rate of about 30% could be obtained.
__________
Translated from Journal of Triticeae Crops, 2008, 28(1): 1–5 [译自: 麦类作物学报] 相似文献
103.
104.
利用分别来源于窄叶青8号(ZYQ8)和京系17(JX17)及春江06(CJ06)和台中本地1号(TNI)2个组合的DH群体(分别称为DH-1和DH-2群体),采用非条件及发育QTL分析方法研究水稻茎蘖消长的遗传控制.其中,DH-1群体定位到条件与非条件QTL共44个,分布于第3、12染色体以外的其他10条染色体上;DH-2群体定位到条件和非条件QTL共70个,分布于第7染色体外其他11条染色体上.通过全基因组比较QTL定位,在2个群体间共确定了10对26个处于相似物理位置的QTL位点,其中有6对14个位点均在相同时期内被检测到,很可能包含有控制茎蘖数的主效数量基因,这些QTL位点在显著性、效应值和贡献率均存在较大差异,对其基因本质仍需进一步深入研究. 相似文献
105.
106.
Jiwei Yang Yanzhi Qu Qiong Chen Jihua Tang Thomas Lübberstedt Haochuan Li Zonghua Liu 《Plant Breeding》2019,138(3):259-265
Haploid genome doubling is a key limiting step of haploid breeding in maize. Spontaneous restoration of haploid male fertility (HMF) provides a more promising method than the artificial doubling process. To reveal the genetic basis of HMF, haploids were obtained from the offspring of 285 F2:3 families, derived from the cross Zheng58 × K22. The F2:3 families were used as the female donor and Yu high inducer No. 1 (YHI‐1) as the male inducer line. The rates of HMF from each family line were evaluated at two field sites over two planting seasons. HMF displayed incomplete dominance. Transgressive segregation of haploids from F2:3 families was observed relative to haploids derived from the two parents of the mapping population. A total of nine quantitative trait loci (QTL) were detected, which were distributed on chromosomes 1, 3, 4, 7 and 8. Three major QTL, qHMF3b, qHMF7a and qHMF7b were detected in both locations, respectively. These QTL could be useful to predict the ability of spontaneous haploid genome doubling, and to accelerate the haploid breeding process by introgression or aggregation of those QTL. 相似文献
107.
Traditional breeding methods require more than 6 years to obtain homozygous inbred lines, while isolated microspore culture (IMC) is an effective way to cultivate double haploid homozygous lines in only 2 years. However, low embryogenesis induction frequency in Chinese flowering cabbage remains a key obstacle to the practical application of this technique. Thidiazuron was added at different concentrations to NLN‐13 medium to estimate its effects on microspore embryogenesis and plantlet regeneration. Results showed that three genotypes responded positively. Optimum thidiazuron concentrations produced embryo yields of up to 14.67 embryos per bud and increased microspore embryogenesis frequency with up to 100% survival. Plantlet regeneration rates were up to 81.67%, and the treatment groups showed lower callus formation. We obtained up to 552 diploid plants from the tested genotypes, and the percentage of doubled haploid at different TDZ concentrations showed slight differences, and doubled haploid rates in the three genotypes were above 70%. They showed a high uniformity and can be directly used for hybrid breeding. This method accelerates microspore application in Chinese flowering cabbage hybrid breeding. 相似文献
108.
Production of haploids in bread wheat, durum wheat and hexaploid triticale crossed with pearl millet
Pearl millet is an efficient alternative to maize as a pollen source for haploid production in bread wheat. To compare haploid production frequencies in other Triticeae species, the crossabilities of two genotypes each of bread wheat, durum wheat and hexaploid triticale with four pearl millet genotypes and a maize control were examined. Embryos were obtained from crosses of all three species with both pearl millet and maize. However, significant differences in crossability were found among the three species (10.5–79.8% seed development and 1.4–15.8% embryo formation), as well as among genotypes of durum wheat (7.2–23.7% and 2.1–6.4%) and hexaploid triticale (0.3–20.6% and 0.1–2.7%). Crossability of bread wheat with pearl millet was relatively high. Haploid plants were regenerated from crosses of all three species with pearl millet. As in the case of maize crosses, low crossabilities of durum wheat and hexaploid triticale with pearl millet can be attributed to the absence of D-genome chromosomes. 相似文献
109.
Production of all eight genotypes of null alleles at 'waxy' loci in bread wheat, Triticum aestivum L. 总被引:3,自引:0,他引:3
Null alleles of the three loci coding for ‘waxy’ proteins in bread wheat have been identified. Plants carrying different null alleles were collected and segregation of the null alleles in both selfed and doubled haploid progeny of plants simultaneously heterozygous for the null alleles at each of the three loci were examined by sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE). Mendelian segregation of these alleles in both types of progeny was shown, indicating that they can easily be utilized in breeding programmes. Iodine staining of the eight possible null phenotypes showed that only the triple null type had zero amylose in its endosperm starch. 相似文献
110.
大白菜回交导入系群体构建及其遗传分析 总被引:3,自引:1,他引:2
利用大白菜栽培品种的DH系Z16和白菜型油菜自交系L144杂交的F1获得包括119个株系的DH群体。用相同亲本的F1与Z16进行独立回交, 利用25个独立回交的BC2分别得到这些株系的DH系,选择每个BC2的4~6个DH系构建121个株系的BIL群体。进一步利用SSR和SRAP标记构建了DH群体遗传图谱, 由10个连锁群组成, 包括245个分子标记, 总长度714 cM, 平均遗传图距2.9 cM。再以此图谱为参照, 用锚定在染色体上的97个SSR标记研究供体亲本L144的染色体片段在B IL群体中覆盖基因组比率。在BIL群体中来源于L144的基因组片段占0.84% ~35.00% , 平均为11.31% , 接近理论遗传预期值12.50%。在25个BC2的BIL株系中供体亲本L144等位位点占1.69% ~27.36% , 平均为11.03%。 相似文献