英德
有道
百度
谷歌
图片
维基
百科
双显性组合 [shuāng xiǎn xìng zǔ hé]
duplex
- 利用5个具有不同纤维品质性状的品种(系)配制完全双列杂交组合20个,通过亲本和F1的2年随机区组试验发现产量性状的铃重和衣分与环境的互作效应小,不存在母体效应,并以加性遗传效应为主,分别占表型方差的51.2%和65.4%;显性遗传效应所占的比率也较高,分别为32.6%和16.8%.铃重和衣分的群体平均优势较大,分别为13.3%和3.5%,达到了极显著;铃重的超亲优势为2.0%,不显著;衣分为显著的负值(-2.1%).遗传分析与杂种优势结果一致.具体表现在产量性状上,亲本相当配制的组合杂合显性较高,其超亲优势正向显著,而极值亲本(差异较大)所配组合没有超过高亲的.这表明亲本差异小、亲源关系较近的亲本中仍然存在足够的遗传变异或某种机制以创造变异使育种取得更大的进展.相关分析表明了仍然存在严重的品质与产量的负相关,遗传改良的难度较大.
Twenty F1 combinations crossed among 5 varieties and strains different in fiber properties according to complete diallel crossing design were used to evaluate the heterosis and gene action of boll weight and lint percentage in high quality fiber property varieties in Upland Cotton in 1998～1999 for two year successively at Nanjing.It was indicated that there existed small interactions with the environmental factors without maternal effects and the additive gene effect was in chief,attaining to 51.2%and 65.4%respectively for boll weight and lint percentage.The dominant effect was also in higher rate,32.6%and 16.8%respectively.The population mean heterosis of boll weight and lint percentage over the mid-parental mean were relatively prominent 13.3%and 3.5%respectively in extreme significance.However,boll weight showed no significantly surpassing parental F1 heterosis over the better parent based on population mean (2.0%);while the lint percentage expressed significant negative heterosis value (-2.1%).The gene actions were in conformity with the heterosis expression.It was shown clearly that the F1 combinations crossed between parents with similar performances had relatively high dominant effects and significant positive F1 surpassing parental heterosis (F1 heterosis over the better parent);while no F1 combination crossed between the parents with prominent mutual difference surpassed the higher parent in yield components,which indicated that among those parents with less difference and close relationships,there still existed sufficient genetic variation or certain mechanism for creating variation and achieving greater advances in breeding.Correlation analyses also indicated that there still existed severely undesirable negative correlation between yield and fiber properties as well as the difficulties for their simultaneous improvements.
 |
 |
 |
 |
 |
 |
 |
中国词汇量第二的英语词典
更多精彩，登录后发现......
