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991.
为了探明吉林省第一时期(1958—1979年)、第二时期(1980—1999年)和第三时期(2000年以后)培育的水稻品种在遗传改良过程中其农艺性状和叶片光合能力的变化,以不同时期育成的24个水稻品种为材料进行田间随机区组试验,在抽穗后测定并分析其农艺性状、叶片特性和光合功能等指标的变化。结果表明:吉林省第二时期育成品种的产量、有效分蘖数、单位面积穗数、每穗粒数和收获指数较第一时期显著增加,而株高显著降低。第三时期育成品种的单株生物量、剑叶光合能力和单株光合能力比第一期和第二时期显著增加。吉林省水稻品种改良过程中,第二时期较第一时期品种产量的提高,主要是通过农艺性状和叶片特征的遗传改良提高经济系数来实现的;而第三时期与第二时期育成品种的农艺性状和叶片特征变化不大,产量的提高主要是通过提高叶片和植株光合能力,增加生物量来实现的。 相似文献
992.
993.
Rosangela Simeão Adriane Silva Cacilda Valle Marcos Deon Resende Sérgio Medeiros 《Plant Breeding》2016,135(2):246-253
Half‐sib progenies of congo signal grass (Brachiaria ruziziensis Germain & Evrard, syn.: B. eminii, Urochloa ruziziensis) were analysed using a mixed model methodology. The objective was to estimate genetic and phenotypic parameters, predict individual genetic values, estimate correlations between characters associated with biomass production and forage nutritive value and use this information to determine the economic weights to compare three multiplicative selection indices. Individual narrow‐sense heritabilities corrected for inbreeding varied from 0.14 to 0.91 for characters associated with biomass production and from 0.04 a 0.24 for nutritional value characters. The correlations among characters associated with annual biomass production were of high magnitude. In contrast, biomass production characters were negatively correlated with crude protein, acid detergent fibre and lignin. Total dry matter yield, crude protein and regrowth ability were weighted separately in evaluations during wet and dry season or annually in selection indices. Index that considered characters annually resulted in better distribution of forage production along the year than indices that separated wet and dry season production. 相似文献
994.
Genetic diversity and population structure of Indian melon (Cucumis melo L.) landraces with special reference to disease and insect resistance loci 下载免费PDF全文
Lakshamana Reddy D. C. Sudarshini K Venkat Anand C Reddy C. Aswath K. N. Avinash H. Nandini E. Sreenivasa Rao 《Plant Breeding》2016,135(3):384-390
This study was aimed to examine the genetic diversity and population structure of Indian melon landraces with special reference to disease and insect resistance loci. Thirty‐six simple sequence repeat (SSR) markers along with seven markers at disease and insect resistance loci were used for this purpose on a panel of 91 accessions available at Indian Institute of Horticultural Research, Bengaluru, India. Model‐based structure analysis revealed the presence of four groups that were consistent with the results of principal coordinate analysis (PCoA). The delineation of populations was mostly based on geography with improved varieties as a separate group. Ten accessions have been identified to possess beneficial alleles at all the selected disease resistance loci and shall be useful for incorporating multiple disease resistance after phenotypic validation. The results obtained in the current study demonstrate the importance of the Indian melon group as a valuable genetic reservoir and the need to plan strategies for its conservation and utilization in breeding programmes. 相似文献
995.
Exploring genetic diversity of rice cultivars for the presence of brown planthopper (BPH) resistance genes and development of SNP marker for Bph18 下载免费PDF全文
Gandhimani Ramkumar G. D. Prahalada Sherry Lou Hechanova Sung‐Ryul Kim Kshirod K. Jena 《Plant Breeding》2016,135(3):301-308
Brown planthopper (BPH) is the most devastating insect pest in rice‐growing areas. Information on availability of BPH resistance alleles and their sources enhances BPH‐resistant breeding programmes. In this study, 260 highly diversified rice cultivars or breeding lines were screened for the presence of five major BPH resistance genes (Bph10, Bph13, Bph18, Bph20 and Bph21) using gene‐specific markers. The analysis revealed that 137 of the 260 cultivars possess at least one BPH resistance gene. Bph10 was predominant while Bph20 was the least distributed. Moreover, two and three different resistance gene combinations were found in the cultivars. Molecular markers play an important role in molecular breeding programmes. A tightly linked PCR‐based co‐dominant Bph18 marker was developed, which is cost effective and time effective and simpler than available Bph18 CAPS marker (7312.T4A). We strongly believe that the identified BPH‐resistant cultivars can be used as alternative resistance gene sources and also as resource for novel BPH resistance genes. The developed Bph18 marker will be highly useful in molecular breeding applications of BPH‐resistant breeding programmes. 相似文献
996.
Adel H. Abdel‐Ghani Songlin Hu Yongsheng Chen Everton A. Brenner Bharath Kumar Michael Blanco Thomas Lübberstedt 《Plant Breeding》2016,135(4):429-438
This study aimed at developing, characterizing and evaluating two maize phenotypic‐selected introgression libraries for a collection of dominant plant height (PHT)‐increasing alleles by introgressing donor chromosome segments (DCS) from Germplasm Enhancement of Maize (GEM) accessions into elite inbred lines: PHB47 and PHZ51. Different backcross generations (BC1‐BC4) were developed and the tallest 23 phenotype‐selected introgression families (PIFs) from each introgression library (PHB47 or PHZ51) were selected for single nucleotide polymorphism genotyping to localize DCS underlying PHT. The result shows that most PIFs carrying DCS were significantly (α = 0.01) taller than the respective recurrent parent. In addition, they contained larger donor genome proportions than expected in the absence of selection or random mating across all BC generations. The DCS were distributed over the whole genome, indicating a complex genetic nature underlying PHT. We conclude that our PIFs are enriched for favourable PHT‐increasing alleles. These two libraries offer opportunities for future PHT gene isolation and allele characterization and for breeding purposes, such as novel cultivars for biofuel production. 相似文献
997.
Naoki Yamanaka Mio Morishita Tomomi Mori Yukie Muraki Midori Hasegawa Md. Motaher Hossain Yuichi Yamaoka Masayasu Kato 《Plant Breeding》2016,135(5):621-626
Asian soybean rust (ASR) caused by Phakopsora pachyrhizi is one of the most serious soybean (Glycine max) diseases in tropical and subtropical areas. A soybean line, PI 587855, showed a resistance phenotype against ASR pathogens in Japan and South America at high frequency; however, little is known of the genetic control of this resistance and chromosomal location of the corresponding locus. Therefore, the aim of this study was to study the inheritance of PI 587855 resistance and map the corresponding locus with SSR markers aiming to use the linked markers in marker‐assisted selection. In the segregating population, resistance to ASR appeared to be controlled by a single dominant gene. The ASR resistance locus was mapped near to the chromosomal region where the resistant loci, Rpp1 and Rpp1‐b, were previously mapped. Comparative genetic mapping and disease reaction profiles of other seven lines carrying Rpp1 or Rpp1‐b to four Brazilian ASR isolates revealed that the resistance reaction exhibited by PI 587855 was similar to that of Rpp1‐b‐carrying varieties which have useful resistance to South American ASR strains. 相似文献
998.
Cisgenesis and genome editing: combining concepts and efforts for a smarter use of genetic resources in crop breeding 下载免费PDF全文
Teodoro Cardi 《Plant Breeding》2016,135(2):139-147
Plant genetic resources (PGR) represent valuable sources of genetic variability for crop breeding. The development of novel biotechnologies is necessary for increasing the efficiency of their use in pre‐breeding and breeding work. The genome sequencing of hundreds of genotypes and the mining of allele diversity in major crops and populations of landraces and wild relatives allow the isolation of genes underlying characters of interest and their precise modification or transfer into targeted varieties. The technological developments and applications of new plant breeding techniques (NPBT) that maximize the similarity with gene transfer by crossing (cisgenesis/intragenesis) or the accuracy of biotechnological approaches (genome editing) are reviewed. Their potentialities and current limitations as well as the possible advantages of using them separately or combined for the exploitation of PGR in crop breeding are also discussed. Above‐mentioned NPBT tackle some objections to the application of biotechnologies in agriculture and are under review worldwide to assess the possible exclusion from the current regulation systems for genetically modified plants. 相似文献
999.
越橘种质资源的CDDP遗传多样性及聚类分析 总被引:4,自引:2,他引:2
分析保守DNA序列多态性(CDDP)标记在蓝莓中的分布及其与生物性状之间的联系,为蓝莓种质的科学评价和合理开发提供理论指导及技术支持。通过筛选多态性丰富的CDDP引物,对32份蓝莓种质资源的基因组DNA进行扩增,根据统计结果分析品种的遗传多样性及聚类关系。共筛选出17条多态性高、产物清晰易辨的CDDP引物。32份样品共检测到207条带,其中多态性条带188条,比例为90.82%,特异条带17条,比例为8.21%。可以用2条引物组合完全区分32种蓝莓。在种群水平上,有效等位基因数、Nei’s基因多样性指数和Shannon信息指数分别为1.59、0.37和0.56。样本间的遗传相似系数范围在0.44~1.00之间,平均为0.73。在相似系数为0.69时,32个蓝莓种质分为3类,野生种笃斯越桔单独聚为一类,矮丛品种‘Blomidon’和半高丛品种‘Northblue’聚为一类,其他品种聚为一大类。CDDP标记在蓝莓中具有较高的多态性及特异性,与种质的需冷量、抗寒性及果实颜色具有一定的相关性。CDDP技术可有效用于蓝莓种质资源遗传多样性分析、品种鉴定及分子标记辅助育种。 相似文献
1000.
本研究探讨海滨雀稗EST序列中SSR位点的分布特征,开发EST-SSR引物分析其在草坪草种质资源遗传多样性研究中的应用。利用SSRIT软件对81220条海滨雀稗EST序列进行SSR位点搜索,分析EST-SSR的分布和特点,并利用Primer 3.0软件设计50对引物,选择10份草坪草对引物进行有效性和多态性检测。结果表明,从13705条海滨雀稗EST序列中检测到了22721个SSR位点,出现频率为16.87%。三核苷和单核苷酸重复为主要类型,所占比例分别为31.71%和29.28%。在检测到的163种基元中,出现最多的重复基元是A/T,其次是CCG/CGG和AGC/CTG。选择合成了50对EST-SSR引物,以海滨雀稗‘Adalady’基因组DNA为模板进行PCR扩增,其中37对引物能扩增出条带。利用这些引物对10份草坪草品种进行多态性检测,其中12对引物的扩增结果具有多态性。利用开发的EST-SSR标记对10份草坪草进行聚类分析,可将其分为4类。利用海滨雀稗EST序列开发SSR标记是可行的,开发的EST-SSR标记能有效用于草坪草遗传多样性研究。 相似文献