Department of Plant Breeding & Biometry, 252 Emerson Hall, Cornell University, 14853-1902, Ithaca, NY, USA.
Theor Appl Genet. 1996 May;92(6):637-43. doi: 10.1007/BF00226083.
Ten elite inbred lines (four japonica, six indica), chosen from those widely used in the hybrid rice breeding program at Human Hybrid Rice Research Center in China, were crossed to produce all possible hybrids excluding reciprocals. The 45 F1 hybrids along with the ten parents were evaluated for eight traits of agronomic importance, including yield potential, in a replicated field trial. The ten parents were analyzed with 100 arbitrary decamer oligonucleotide primers and 22 microsatellite (simple sequence repeats, SSRs) primer sets via polymerase chain reaction (PCR). Out of the 100 random primers used, 74 were informative and amplified 202 non-redundant bands (variants) with a mean of 2.73 bands per polymorphic primer. All 22 microsatellite primer sets representing 23 loci in the rice genome showed polymorphisms among the ten parents and revealed 90 alleles with an average of 3.91 per SSR locus. Cluster analysis based on Nei's genetic distance calculated from the 291 (202 RAPDs, 89 SSRs) non-redundant variants separated the ten parental lines into two major groups that corresponds to indica and japonica subspecies, which is consistent with the pedigree information. Strong heterosis was observed in hybrids for most of the traits examined. For the 43 diallel crosses (excluding 2 crosses not heading), yield potential, its components (including panicles per plant, spikelets per panicle and 1000-grain weight) and their heterosis in F1 hybrids showed a significant positive correlation with genetic distance. When separate analyses were performed for the three subsets, yield potential and its heterosis showed significant positive correlations with genetic distance for the 15 indica x indica crosses and the 6 japonica x japonica crosses; however, yield potential and its heterosis were not correlated with genetic distance for the 22 indica x japonica crosses. Results indicated that genetic distance measures based on RAPDs and SSRs may be useful for predicting yield potential and heterosis of intra-subspecific hybrids, but not inter-subspecies hybrids.
从中国杂交水稻研究中心广泛用于杂交水稻育种计划的 10 个近交系（4 个粳稻，6 个籼稻）中选择了 10 个精英系进行杂交，产生了所有可能的杂交种，不包括互交。在一个重复的田间试验中，对 45 个 F1 杂种及其 10 个亲本进行了 8 个农艺性状的评估，包括产量潜力。用 100 个任意十聚体寡核苷酸引物和 22 个微卫星（简单重复序列，SSR）引物通过聚合酶链反应（PCR）对 10 个亲本进行了分析。在使用的 100 个随机引物中，74 个是信息性的，扩增了 202 个非冗余带（变体），每个多态性引物平均有 2.73 个带。所有代表水稻基因组 23 个位点的 22 个微卫星引物在 10 个亲本中均表现出多态性，显示 90 个等位基因，每个 SSR 位点平均 3.91 个。基于 Nei 遗传距离的聚类分析从 291 个（202 个 RAPD，89 个 SSR）非冗余变体中分离出 10 个亲本系，分为两个主要组，对应于籼稻和粳稻亚种，这与系谱信息一致。大多数性状的杂种都表现出强烈的杂种优势。对于 43 个完全双列杂交（不包括 2 个未结实的杂交），产量潜力及其组成部分（包括每株穗数、每穗小穗数和千粒重）及其在 F1 杂种中的杂种优势与遗传距离呈显著正相关。当分别对三个子集进行分析时，产量潜力及其杂种优势与 15 个籼稻 x 籼稻杂交和 6 个粳稻 x 粳稻杂交的遗传距离呈显著正相关；然而，22 个籼稻 x 粳稻杂交的产量潜力及其杂种优势与遗传距离不相关。结果表明，基于 RAPD 和 SSR 的遗传距离测量可能有助于预测亚种内杂种的产量潜力和杂种优势，但不适用于亚种间杂种。
