Oryza sativa and O. latifolia belong to the AA and CCDD genomes of Oryza, respectively. In this study, interspecific hybrids of these species were obtained using the embryo rescue technique. Hybrid panicle traits, such as long awns, small grain, exoteric large purple stigma, grain shattering and dispersed panicles, resemble that of the paternal parent, O. latifolia, whereas there is obvious heterosis in such respects as plant height, tillering ability and vegetative vigor. Chromosome pairing and the genomic components of the hybrid were subsequently investigated using genomic in situ hybridization (GISH) and fluorescent in situ hybridization (FISH) analysis. Based on the mitotic metaphase chromosome numbers of the root tips investigated, the hybrid is a triploid with 36 chromosomes. The genomic constitution of the hybrid is ACD. In the meiotic metaphase I of the hybrid pollen mother cell, poor chro- mosome pairing was identified and most of the chromosomes were univalent, which resulted in com- plete male sterility in the hybrid.
YI ChuanDeng TANG ShuZhu ZHOU Yong LIANG GuoHua GONG ZhiYun GU MingHong
T0135是2009年从中籼3037第11染色体短臂端三体(2n+11S·)自交后代中发现的形态变异株.选用第11号染色体着丝粒区域的特异分子细胞学标记5S rDNA进行染色体荧光原位杂交(fluorescent in situ hybridization,FISH)分析,发现T0135是第11染色体短臂双着丝粒染色体.为了研究该双着丝粒染色体有性繁殖过程中的遗传稳定性,对T0135有性繁殖后代进行FISH分析,观察后代中染色体类型并进行统计,发现后代染色体类型与亲本类型相同的占94%,即双着丝粒染色体能进行正常的减数分裂,通过着丝粒特异组蛋白(centromere specific histone H3,CENH3)免疫检测确定在双着丝粒染色体中只有一个有CENH3信号,说明该双着丝粒材料中只有一个行使正常功能的着丝粒,另外一个着丝粒处于失活状态.
From the progenies of a telotrisomic of chromosome 9 short arm of an indica rice variety, Zhongxian 3037, a phenotypical variant was selected. The variant plant had rolled leaves, dispersed plant type, as well as a low seed-setting rate. Cytological and molecular cytological investigations revealed two extra chromosomes, which were the shortest in somatic cells of the variant. Fluorescent in situ hybridization (FISH) analysis using a rice centromere specific DNA (RCS2) and a DNA sequence specific for chromosome 9 on premetaphase and pachytene chromosomes showed that these two chromosomes were the short arms of chromosome 9. That is to say, the variant was a telotetrasomic of chromosome 9. Among the 25 pachytene cells, the two telosomic chromosomes paired each other to form a bivalent and didn’t pair with other normal chromosome 9 as multivalents in 96% cells. However, the bivalent was easy to disassociate in advance.
GONG Zhi-yun GAO Qing-song Yu Heng-xiu YI Chuan-deng Gu Ming-hong
