水稻黄华占背景选择导入系的耐低氮筛选评价与利用OA北大核心CSTPCD

Nitrogen deficiency in medium-yield and low-yield fields is an important factor restricting the high yield in rice.It is one of effective ways to solve the problem by screening and developing rice variety with low nitrogen tolerance(LNT).In this study,the selected introgression lines(SILs)from germplasms in Huanghuazhan(HHZ)background were used to evaluate the performance of yield and its related traits under low and normal nitrogen conditions for successive three seasons.Low nitrogen had least effect on heading date,seed fertility,and 1000-grain weight(TGW)with the average low nitrogen tolerance index(LNTI)around 1.0,whereas had greatest effect on grain yield per plant(GYP)and panicle number per plant(PN)with the respective average LNTI of 0.45 and 0.62,indicating that GYP and PN were useful indicator of LNT.Based on LNTI of GYP,nine LNT lines were selected with LNTI ranging from 0.87 to 1.04.Five of the selected LNT lines verified by multiple-site trials,one line(M281)had low LNT with GYP-LNTI of 0.66 and the other four had high LNT with the average GYP-LNTI of 0.94,indicating that LNT was a characteristic with the differences at individual and population levels,thus emphasizing the importance of popula-tion verification for LNT materials which were screened from segregation population.Among the four LNT lines,M85 was mainly achieved by higher PN and TGW under low nitrogen condition,whereas the other three lines(M382,M563,and M79)were mainly supported by more filled grains per panicle(FGP)and higher TGW.Therefore,an important way was proposed to achieve high yield under low nitrogen condition through increasing FGP based on a relatively high PN.In view of salt tolerance at seedling stage,drought tolerance at reproductive stage and LNT at all growth duration of SILs,it was discussed how to simulta-neously improve multiple complex abiotic stress tolerances using SILs derived from diverse donors by molecular design.