旱稻(Oryza sativa)×长芒稗(Echinochloa caudata)远缘杂交后代结实率及杂种优势分析

以旱稻基因型旱 65(OryzasativaL .)为母本 ,稗草长芒稗 (Echinochloacaudata)为父本进行远缘杂交 ,获得实粒种子。连续 5年试验结果表明 :( 1 )F0 高度不孕 ,并伴有杂交种发育夭折现象。去雄 82 4朵小花 ,结实率为 1 2 1‰。 ( 2 )F1杂种优势明显 ,育性正常 ,结实率 92 2 6% ,单株产量超母本 80 3 9%。 ( 3 )F2 农艺性状分离严重 ,但育性无分离。群体 40 5株无不育株出现。选育出的优良变异单株“远F2 1” ,超亲优势为 55 64%。 ( 4)对“远F2 1”衍生F3株系 1 60株考种株穗数、株高、穗长、主茎穗一级枝梗数、穗总粒数、穗实粒数诸性状 ,平均超亲优势分别为 2 3 2 %、1 5 1 8%、47 2 6%、3 3 84%、2 4 2 6%及 2 1 62 % ,差异显著。 ( 5)F5光合速率测定 ,超母本2 9 72 %。远缘杂交对不同属间引入目的基因 ,非常有效。

STUDY ON SEED SET AND HETEROSES OF DISTANT CROSS OF UPLAND RICE( Oryza sativa) ×LONG-AWN-BARNYARD-GRASS( Echinochloa caudata)

years successive observation on progenies of a distant cross of upland rice Han 65( Oryza sativa) ×Long\|awn\|barnyard\|grass( Echinochloa caudata), a summer dominant native grass showed that.(1)F\-0 generation was highly infertile,seed set was only 1\^21‰,which coincided with seed abortion under multiple repeating pollination on about 800 florets.(2)F\-1 generation performed very good heteroses and good fertility,the seed set was 92\^26% and yield advantage was 80\^39% over its female.(3)Wild segregating were happened on agronomic characters but none for fertility in F\-2 one.There was no sterile plant observed in the total of 405 plants.(4)“Yuan F\-2\|1”,a excellent variant plant selected from F\-2′s,whose yield advantage was 55\^64% over its female.Characteristics of heads/plant,plant height,first branches of main stem,florets/main stem,seeds/main stem as well as seed set/main stem were recorded from 160 plants of F\-3 derived from “Yuan F\-2\|1”.Heterosis of them was 1\^02%,15\^18%,47\^26%,33\^84%,24\^62% and 2\^27%,respectively.Differences were significant comparing with its maternal by means of variance analysis.(5)Photosynthetic rate of F\-5 was 29\^72% higher than that of parent,Han 65.