光敏不育粳稻及其杂交后代的光周期效应指数(PE)分析

Analysis of the Photoperiodic Effect Index (PE) of Two Photo-sensitive Genie Male Sterile Japonica Rice and Their Hybrid Offsprings

作者通过剥蘖分株,把供试水稻每一单株的4个第1次分蘖分别栽培在高温长日(光照时数/平均气温为15小时/28.4℃)、低温长日(15小时/23.5℃)、高温短日(10小时/28.4℃)和低温短日(10小时/23.5℃)环境下,在对号统计供试个体分株苗的育性(花粉败育度和小穗不育率)、计算个体光周期效应指数(PE,等于长日与短日植株育性之差)的基础上,分析了光敏不育粳稻(农垦58s、7001s)及它们的杂交F_1、BF_1和F_2个体、群体的PE.结果表明:1.农垦58s和7001s群体的PE以花粉败育度(或小穗不育率)为指标时大于50%(或 6.4%).温度处理间差异不显著.2.F_1群体的PE表现超亲优势.3.BF_1和F_2个体的PE(A)或PE(B)(分别表示以花粉败育度或小穗不育率为指标的PE)的变异远大于双亲.PE(A)的遗传力估值为82.0%(高温环境)和71.8%(低温环境);PE(B)的遗传力估值为58.0%与14.8%.4.F_2个体的PE(A)或PE(B)呈偏态的双峰连续分布.其中有约5%的PE(A)、10%的PE(B)高于双亲的最高值.据此研究结果,作者建议光敏不育水稻育种应注重对PE性状的选择.

By growing the 4 primary tillers of a rice plant into 4 separated plants, the au-thores made it possible to study the effect of day-length (LD and SD) and temperature (HT and LT) on the fertility of each individual of the materials tested. Thus, each individual (actually the 4 tiller-plants) was (were) put under the following 4 kinds of environmental conditions, i. e. LDHT(15 hr. /28. 4℃), LDLT(15 hr. /23. 5℃), SDHT(10 hr./28.4℃) and SDLT(10hr. / 23. 5℃). And the fertility (abortive pollen % and sterile spikelet %) of each tiller-plant was scored. The photoperiodic effect indices (PE) were calculated by subtracting the SD date from the LD date for the abortive pollen %, PE(A), and sterile spikelet %, PE(B), respectively. Comparison of the PE values revealed:1. The PE(A) (or PE(B)) value was more than 50% (or 6. 4%) in Nong ken 58 s(N-K. 58 s) and 7001 s populations. No significant difference was observed between the 2 different temperature treatments.2. The mean PE values of F1 population of cross N-K. 58 s and 7001 s showed over-domi-nant heterosis.3. The variabilities of the PE(A) and PE(B) of the BF1 and the F2 individuals were f ar more larger than those of both parents. The estimate of broadsense heretability of PE(A) were 82. 0% (HT) and 71. 8% (LT), while those of PE(B) were 58. 0% and 14. 8% respectively.4. The distributions of the PE(A) and PE(B) of the F2 individuals were continuous, showing bimodal, shewed curves. There were transgressive segregates on both sides of the curves. About 5% of the segregates had PE(A) and 10% had PE(B) higher than the highest PE values of both parents,Based on the above results, the authors suggested that selection for higher PE value should be emphasized in breeding for photo-sensitive genie male sterile rice.