新选粳稻BT型同质恢复系农艺和品质性状的配合力研究

Combining Ability for Agronomic and Quality Characters of BT Type Iso-cytoplasmic Restorer Lines Newly Bred in Japonica Rice (Oryza sativa L.)

利用4个粳稻BT型不育系和5个新选粳稻BT型同质恢复系及4个非同质恢复系通过NCⅡ设计共配36个组合,对杂种一代8个农艺性状和10个品质性状的表现及亲本的配合力进行了研究。结果表明:(1)除播抽历期、千粒重和单株有效穗3性状外,同质恢复系所配杂种的其他农艺性状与非同质恢复系所配杂种相比均有所降低,但就单株产量而言,同质恢复系与非同质恢复系差异不显著,同质恢复系所配杂种的农艺性状更加协调。(2)从品质性状的平均表现看,与非同质恢复系相比,同质恢复系增加杂种F1的糙米率1.07%,粒宽0.08mm,差异极显著;提高杂种精米率0.83%和整精米率0.74%,降低杂种垩白米率0.46%和垩白度0.54%,但差异不显著;同质恢复系改善了杂种的糙米率和粒宽。(3)在农艺性状上,一般配合力好的不育系是4016A和镇稻88A,恢复系是六千辛R、C418和湘晴;在品质性状上,一般配合力好的不育系是4016A和青空A,恢复系是6427R、武育粳3R和六盐189R;综合农艺和品质性状,4016A和镇稻88A是较优的不育系亲本,6427R、六盐189R和湘晴是较优的恢复系亲本。(4)农艺性状优良的组合是4016A/773021、越光A/C418和镇稻88A/C418;品质性状优良的组合是4016A/3726R、4016A/六千辛R和青空A/HP122;综合性状优良的组合是4016A/武育粳3R、4016A/湘晴和镇稻88A/6427R。

Seven million hectares are planted with japonica rice in China yearly. The area of japonica hybrid rice planted annually was less than 10% though the first commercial hybrid cultivar was released in 1975. The major reasons for this (situation) are that heterosis over pure line check cultivar is not conspicuous and grain quality of hybrids is inferior to pure line check cultivar. In order to use the achievements of pure line breeding for enhancing the standard heterosis and improving grain quality of hybrid rice, several new CMS and restorer lines with BT type cytoplasm have been bred by backcross method using commercial cultivars as recurrent parents in japonica rice. In our previous paper, the results of combining ability analyses of agronomic and quality characters of BT type CMS lines newly bred were reported (Li and Hong, 2004). The objective of this paper was to research the combining ability for agronomic and quality characters of BT type iso-cytoplasmic restorer lines newly bred. Iso-cytoplasmic restorer line means the restorer line with the same cytoplasm as CMS line, and that lines with normal or unknown cytoplasm are referred to as non-isocytoplasmic restorers. Four CMS lines, five iso-cytoplasmic restorers and 4 non-isocytoplasmic restorers were used as parents. With NCⅡ genetic design, 36 combinations (4×9) were made by paper bag isolation. The plots of F_1s and parents were arranged in the field in a randomized complete block design with 2 replications. Eight agronomic traits and 10 quality characters were investigated. Research results were as follows: (1) The average phenotypic values of the hybrids produced by iso-cytoplasmic restorers were lower than that by non-isocytoplasmic restorers in agronomic traits except days from sowing to heading, 1 000-grain weight and panicles per plant, but the difference between the two kinds of hybrids in yield per plant was not significant, indicating that agronomic traits of hybrids produced by iso-cytoplasmic restorers were more harmonious (Table 4). (2) For quality characters, in the hybrids produced by iso-cytoplasmic restorers the brown rice percentage was increased by 1.07 %, and grain width by 0.08 mm, the differences were highly significant, as compared with that by non-isocytoplasmic restorers. Also in the hybrids produced by iso-cytoplasmic restorers the milled rice percentage was increased by 0.83%, and head rice percentage by 0.74%, chalkiness score was decreased by 0.46%, and rate of chalkiness by 0.54%, but the differences were not significant, as compared with that by non-isocytoplasmic restorers. These results indicate that brown rice percentage and grain width are improved in hybrids produced by iso-cytoplasmic restorers (Table 7). (3) For agronomic traits, 4016A and Zhendao88A were elite CMS lines, while Liuqianxin R, C418 and Xiangqing elite restorers in terms of GCA (Table 5). For quality characters, CMS lines 4016 A, QingkongA and the restorers 6427R, Wuyujing 3R, Liuyan189R had good GCA ((Table 8).) Considering both agronomic and quality characters, 4016A and Zhendao 88A were the ideal CMS lines, while 6427R, Liuyan 189R and Xiangqing the superior restorers. (4) 4016A/77302-1, Yueguang A/C418 and Zhendao 88A/C418 were excellent combinations in terms of agronomic traits; 4016A/3726 R, 4016 A/Liuqianxin R and Qingkong A/HP122 were excellent combinations in quality characters. 4016A/Wuyujing 3R, 4016A/Xiangqing and Zhendao 88A/6427R were excellent combinations in both agronomic and quality characters.