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181.
为了给ISSR标记技术应用于小黑麦杂种鉴定提供参考,利用ISSR标记对小黑麦品系P1和P_2有性杂交得到的F_1代群体进行分子鉴定,同时结合田间表型调查结果对F_1代群体进行遗传多样性分析。结果表明,66个杂交F_1代单株中,52个为真杂种,其中,5个单株无主茎、未结实,1个生长后期死亡。14条ISSR引物对46个正常结实真杂种扩增的多态性条带百分率为61.19%,其中,UBC822的多态性条带百分率为100%,UBC808和UBC815的多态性条带百分率均为75%。F_1代群体和父母本的遗传相似系数为0.62~0.94,说明杂交后代产生了丰富的遗传变异。聚类分析将杂交F_1代群体和父母本在阈值0.748处分为3大类群,第1类群包括1份材料(父本,P1),第2类群包括1份材料(母本,P_2),第3类包括46个杂交F_1代单株;杂交F_1代与父母本的遗传距离较远,先与母本聚为一类,之后与父本聚为一类。田间调查结果表明,7个性状中,除株高偏向于父本外,分蘖数、有效分蘖数、穗长、小穗数、穗粒数和穗粒重均偏向于母本,与父本的差距较大,这与ISSR分析结果基本相吻合。 相似文献
182.
Shinya Kasajima Chidori Katagiri Toshikazu Morishita Tatsuro Suzuki Yuji Mukasa 《Plant Production Science》2017,20(4):384-388
Common buckwheat is a self-incompatible, insect-pollinated allogamous plant. This study examined growth and yield of the common buckwheat self-compatible and hybrid lines pollinated with and without flies. Self-compatible ‘IH3’, hybrid ‘IP2/IH3’, and standard self-incompatible ‘Kitawasesoba’ were used in field and pot experiments. Self-compatibility of ‘IH3’ was shown to be of high purity. Approximately 10% segregation of pin plants from ‘IP2/IH3’ was observed. The harvest index of ‘Kitawasesoba’ pollinated without flies was considerably lower than that pollinated with flies in both field and pot experiments. The harvest index values of ‘IH3’ and ‘IP2/IH3’ were hardly affected by the presence or absence of flies. The morphological traits of ‘IH3’ were significantly lower than those of the other two genotypes. Large differences in these traits between ‘IP2/IH3’ and ‘Kitawasesoba’ were not observed in either the field or pot experiments. The seed yield of ‘Kitawasesoba’ pollinated without flies tended to be lower than that pollinated with flies. The seed yield of ‘IP2/IH3’ tended to be higher than that of ‘IH3’. The hybrid line ‘IP2/IH3’ showed a high fertilization rate, which was nearly as high as that of ‘IH3’. Rate of fertilization and percentage of ripe seeds were higher in ‘IH3’ and ‘IP2/IH3’, wherein they were hardly affected by the presence or absence of flies, than in ‘Kitawasesoba’. The ‘IP2/IH3’ hybrid line will be useful for understanding the stable high-yielding ability of self-compatibility common buckwheat. 相似文献
183.
Genetic divergence in two tropical maize composites after four cycles of reciprocal recurrent selection
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Adesike O. Kolawole Abebe Menkir Melaku Gedil Essie Blay Kwadwo Ofori Jennifer G. Kling 《Plant Breeding》2017,136(1):41-49
Two tropical maize composites were subjected to four cycles of reciprocal recurrent selection to develop divergent inbred lines with good combining ability. This study was conducted to examine the extent of genetic diversity, changes in allele composition and genetic structure, of 100 randomly selected S1 lines each from the original (C0) and advanced (C4) selection cycles of TZL COMP3 and TZL COMP4, genotyped using single nucleotide polymorphism (SNP) markers. Results revealed that the proportion of alleles at both low and high frequencies decreased from C0 to C4, whereas those at intermediate frequencies increased at C4 in the two composites. More unique and other alleles were lost at C4 in TZL COMP3 relative to those in TZL COMP4. The changes in different measures of genetic diversity were either small or negligible with selection in the two composites. The proportion of markers departing from Hardy–Weinberg equilibrium (HWE) decreased with selection, whereas the total number of pairs of markers in linkage disequilibrium increased with selection in the two composites. Examination of changes in population structures using a model‐based approach as well as cluster and multivariate analyses found a high degree of concordance in stratifying the 400 S1 lines into four non‐overlapping groups corresponding to the two selection cycles each within the reciprocal composites. The observed molecular‐based divergence between cycles within the same composite and the clear differentiation between the complementary composites highlight the importance of reciprocal recurrent selection for preserving genetic diversity for long‐term selection. This increases the potential of the advanced selection cycles to sustain genetic gain in productivity of hybrids adapted to the savannas in West and Central Africa. 相似文献
184.
Interspecific cross‐hybrids of Nicotiana tabacum L. cv. (gla.) S ‘K326’ with Nicotiana alata
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Jugou Liao Jinran Dai Shiyi Yang Xiaoli Zhou Longhui Ren Zhuangzhuang Chen Haili He Suiyun Chen 《Plant Breeding》2017,136(3):427-435
In order to introduce the Tomato Spotted Wilt Virus (TSWV) resistance from Nicotiana alata into Nicotiana tabacum, a cytoplasmic male sterility (CMS) line of N. tabacum (N. tabacum L. cv. (gla.) S ‘K326’), was successfully crossed with N. alata. Despite a high DNA content variability, F1 hybrids could be classified in two subgroups, a major one encompassing fertile hybrids morphologically similar to their tobacco maternal parent but TSWV sensitive, and a minor one displaying sterile hybrids showing an intermediate phenotype and TSWV resistant. In order to elucidate the unexpected fertility recovery of the fertile F1 plants, some N. alata fertility restoration ppr genes were cloned and were shown to be differentially expressed between parental lineages as well as between both F1 subgroups, suggesting that N. alata contains fertility restoring allele able to overcome the CMS of N. tabacum. 相似文献
185.
Jawahar Lal Katara Ram Lakhan Verma Debkanta Nayak Umakanta Ngangkham Soham Ray Hatanath Subudhi Lambodar Behera Sanghamitra Samantaray Ravi Nageswara Rao Onkar Nath Singh Trilochan Mohapatra 《Plant Breeding》2017,136(1):74-82
Identification of new parental lines is crucial for developing ecology‐specific hybrids with ideal agronomic performance. We screened a total of 570 different ecology‐specific Indian rice varieties for the presence of fertility restorer genes, Rf3 and Rf4 using tightly linked markers DRRM Rf3‐10 and RM6100, respectively. Among these varieties, 13% carried Rf3Rf3/Rf4Rf4, 31% carried rf3rf3/rf4rf4, 6% carried Rf3Rf3/rf4rf4 and remaining 50% carried Rf4Rf4/rf3rf3 allelic combinations. A mini set of 40 varieties with variable allelic combinations of fertility restorer genes were testcrossed with WA and Kalinga‐based CMS lines. All the 80 F1s were evaluated for spikelet fertility and fertility restoration ability. Rf3Rf3/rf4rf4 genotypes mostly behaved as partial maintainers or partial restorers. In contrast, rf3rf3/Rf4Rf4 genotypes were partial or effective restorers. However, double dominant genotypes showed better fertility restoration than the genotypes containing Rf3 or Rf4 individually. Some of the genotypes showed unexpected restoration pattern implying occurrence of other fertility restorer(s) apart from Rf3 and Rf4. The perfect restorers and maintainers identified in this study can be directly used in hybrid rice breeding. 相似文献
186.
Comparing mating designs to restore seed production of interspecific hybrids between Trifolium repens (white clover) and Trifolium uniflorum
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Muhammad Naeem Isabelle Marjorie Verry Peter D. Kemp James P. Millner Warren Mervyn Williams 《Plant Breeding》2017,136(3):420-426
Interspecific hybrids between Trifolium uniflorum and cultivated white clover (Trifolium repens) have highly useful characteristics for temperate pastoral systems derived from both parent species. However, the early hybrids (F1 and BC1) also have unacceptably poor seed production for commerce. This study analysed the basis for the poor seed production and investigated breeding strategies for overcoming the problem. The BC1F1 generation produced lower‐than‐expected numbers of heads per plant and seeds per floret. Backcrossing of selected hybrids to white clover corrected these deficiencies and created new variation. Seed numbers were also returned to near target levels by recurrent selection within the BC1 generation. Thus, it was possible to retain a theoretical average of 25% of T. uniflorum genome and still achieve high seed production per plant. The BC1F2 and BC2F1 generations produced high seed numbers per plant, along with reasonable variation. Both of these second‐generation hybrid forms have high reproductive potential and should be the focus for the selection of the desired combinations of agronomic and seed production traits. 相似文献
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脉冲电流烧结过程的颈部形成机理,特别是非导电粉末材料,是需要着重研究的核心问题。以非导电Al2O3粉末为研究对象,引入L-S(Lord and Shulman)型广义热弹性方程,初步探究烧结初期非导电粉末颈部局部高温形成以及快速烧结机理。利用Comsol Multiphysics模拟得到脉冲电流烧结过程中颗粒内部的温度场和应力场分布以及烧结颈部的化学势和空位浓度变化规律。数值结果表明,热以波的形式在烧结颈部产生叠加,形成局部高温。化学势变化表明:烧结初期表面扩散占主要作用,空位浓度差的突变使烧结颈部产生局部空位浓度梯度,促进烧结颈长过程,缩短烧结时间。 相似文献