| In rice breeding currently, it has been a hot and key research direction to explore the indica-japonica inter-subspecific heterosis to develop high-yielding rice varieties. Using indica-japonica hybrid technology, part segment of japonica gene resources could be introduced into indica genetic backgrounds by means of gene introgression to breed derivative lines form indica-japonica crossing. These derivatives will have an effective improvement in productivity and stress resistance in indica-indica hybrid rice and indica-japonica hybrid rice of japonica sterile line×indica restoring line. Ninety-nine derivative lines form four indica-japonica crossing were analyzed the indica-japonica attributes, InDel genetic distance (GD), cluster analysis by nineteen pare of primers selected from InDel molecular marker. Their genetic backgrounds have been understood with InDel marker testing and qPL6 locus testing. Fifteen agronomic traits of derivatives from four crossings, eleven agronomic traits of combinations from crossing with indica sterile line 9311A and japonica sterile line ZheO4A were investigated to analysis the character expression, competitive heterosis (CH), the correlation ship among the CH of every characteristic, and between with InDel genetic distance of two parents. The main results were as follows:The agronomic traits of derivatives from four crossings were investigated, it was found that the averages of height of derivatives of YT (Y92×Tainongxinzhan) and YF (Y92×Fanfengruanzhan) are shorten and the stem diameter of culm base are broaden compared with high value of parent, on the contrary, the averages of height of derivatives of YY (Y92xYueqixinzhan) and YJ (Y92×Jinshengruanzhan) are heighten and the stem diameter of culm base are attenuated. The panicle traits of spikelet number per panicle, fertile spikelet number per panicle, number of primary branch, number of secondary branch were increased more or less than high values of parent. In addition to YT derivatives, weights per panicle of derivatives from other three crossing were increased than high values of parent.The indica-japonica attributes of derivatives form four indica-japonica crossings were analyzed by nineteen pare of InDel molecular marker. It was shown that nineteen two derivatives belong to typical indica type,11 one belong to indica type and 6 one is type of indica cline among derivatives from YT crossing. Among 7 derivatives from YY crossing, one belongs to typical indica type,2 belong to indica type and 4 is indica cline. As the 60 derivatives from YF crossing,32 materials belong to indica type and 28 one belong to indica cline. For 13 derivatives from YJ crossing,9 materials belong to indica type and four one belong to indica cline. Compared between the results of indica-japonica attributes with cluster analysis, it consisted with in YT and YY derivatives. It was effective to detect qPL6 locus using three pare of InDel primer for derivatives.80 derivatives were carried with qPL6 locus and 19 one were no this gene in 99 tested derivatives. The primary branch was statistic for all derivatives,93 one were more or equate to 17 branch, only 6 one is less than 17.The F1 expression of combinations of derivatives from four crossings crossed with indica sterile lines 9311A were investigated, results show that they have higher yield level and apparent heterosis. As soon as the grain weights per plant, the rank is YT series>YF series> YY series> YJ series. Analysis of the factor contribution to yield among various series combination, the factor contribution to yield in YT series are effective tiller number and fertile spikelet number per panicle, it is fertile spikelet number per panicle weight in YF series, and is fertile spikelet number in YY series. Also, The F1 of combinations of derivatives from four crossings crossed with japonica sterile lines Zhe04A were founded sterile or partial sterile. Their period duration is delayed, plant height is shorten and fertile spikelet number per panicle is decreased compared to their male parent. At Fengliangyou 4 as control,24 combinations are increased by 50% in yield.The correlation of competitive heterosis of various traits among combinations form 9311A were analyzed. In group of combinations increased by 50%, the CH of grain weight per plant is significantly positive correlate with the CH of tiller number, panicle length and seed set, and it is significantly negative correlate with the CH of plant height. The CH of grain weight per panicle is significantly positive correlate with the CH of period duration, fertile spikelet number per panicle, seed set and 1000-grain weight, but it is significantly negative correlate with the CH of tiller number. Compared with above group, in group of combinations increased more than 0%, the traits significantly positive correlate with the CH of grain weight per panicle add fertile spikelet number per panicle and cut down seed set, plant height is also negative correlate with that one. If 99 combinations as a group, beside of period duration and plant height, CH of eight traits have significantly or most significantly positive correlation with CH of grains weight per plant. Meanwhile CH of seven traits,1000-grian weight and so on, is significantly or most significantly positive correlation with CH of grains weight per plant.The correlation between competitive heterosis of various traits among combinations form 9311A with the InDel GD of two parents were analyzed. In group of combinations increased by 50%, the CH of grain density, grain weight per panicle,1000-grain weight and fertile spikelet per panicle are significantly positive correlate with the InDel GD of two parents. Meanwhile, in group of combinations increased more than 0%, only the CH of grain density is significantly positive correlate with the InDel GD of two parents. At group of combinations decreased, the CH of 1000-grain weight and seed set are significantly positive correlate with the InDel GD, and tiller number is significantly negative correlate with the InDel GD. If all combinations as a group, no CH of traits is found correlate with the InDel GD. |
PDF Full Text Request