例句與造句

1. 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
   利用5個具有不同纖維品質(zhì)性狀的品種(系)配制完全雙列雜交組合20個,通過親本和f1的2年隨機區(qū)組試驗發(fā)現(xiàn)產(chǎn)量性狀的鈴重和衣分與環(huán)境的互作效應(yīng)小,不存在母體效應(yīng),并以加性遺傳效應(yīng)為主,分別占表型方差的51 . 2 %和65 . 4 % ;顯性遺傳效應(yīng)所占的比率也較高,分別為32 . 6 %和16 . 8 % .鈴重和衣分的群體平均優(yōu)勢較大,分別為13 . 3 %和3 . 5 % ,達到了極顯著;鈴重的超親優(yōu)勢為2 . 0 % ,不顯著;衣分為顯著的負值( - 2 . 1 % ) .遺傳分析與雜種優(yōu)勢結(jié)果一致.具體表現(xiàn)在產(chǎn)量性狀上,親本相當配制的組合雜合顯性較高,其超親優(yōu)勢正向顯著,而極值親本(差異較大)所配組合沒有超過高親的.這表明親本差異小、親源關(guān)系較近的親本中仍然存在足夠的遺傳變異或某種機制以創(chuàng)造變異使育種取得更大的進展.相關(guān)分析表明了仍然存在嚴重的品質(zhì)與產(chǎn)量的負相關(guān),遺傳改良的難度較大
2. It's difficult to find additive gene in a sentence. 用additive gene造句挺難的