OsNramp5基因敲除对水稻产量的影响

Effects of OsNramp5 Gene Knockout on Rice Yield

利用华占、五山丝苗、中早35和五丰B等4个品种背景的多个OsNramp5基因敲除株系及其原始品种(对照)作为供试材料,在3个不同环境采用随机区组设计进行了小区产量的比较试验。试验结果表明:虽然OsNramp5基因敲除材料显示出了优越的降镉特性,但在不同环境中几乎全部表现为不同程度的减产(减幅2.9%~25.6%),在不同OsNramp5基因敲除株系与野生型对照的42次产量比较事件中,减产幅度超过4%并且统计上显著的占比为57.1%,减产幅度超过5%但统计上不显著的占比为28.6%,减幅4%以下但不显著的占比为11.9%,略微增产(仅1例,增幅2.6%)但不显著的占比为2.4%;相同OsNramp5基因敲除材料在不同环境减产幅度不同,多数OsNramp5基因敲除株系的产量变异度比原始品种大,且不同品种背景基因敲除材料在不同环境下的减产幅度波动情况也存在差异,此外,相同品种背景的不同OsNramp5基因敲除株系(不同株系组培中发生的基因组背景突变存在差异)以及一个株系分离后代相同突变基因型不同姊妹系都存在产量显著差异的情况。OsNramp5基因敲除对水稻产量的影响受品种类型、组培突变和环境等因素的综合影响,多数OsNramp5基因敲除材料的稳产性能下降。因此,推荐选择合适品种进行OsNramp5基因敲除,获得基因敲除株系后精心选择优良株系或回交并进行多年多点试验再进行应用。

The plot yield comparison experiments were conducted in 3 different environments by random block design with multiple OsNramp5 gene knockout lines and their original cultivars as test materials,viz.Huazhan,Wushansimiao,Zhongzao 35 and Wufeng B.The results showed that although the OsNramp5 knockout materials showed superior cadmium reduction properties,almost all of them showed varying degrees of yield reduction(2.9%~25.6%)in different environments.Among the 42 yield comparison events between different OsNramp5 gene knockout strains and wild type controls,57.1%showed yield reduction rate more than 4%(statistically significant),28.6%showed a reduction of more than 5%(not statistically significant),11.9%showed a reduction of less than 4%(not significant),and 2.4%showed a slight increase(by 2.6%)in production(only 1 case;not significant).The yield decrease rate of the same OsNramp5 knockout lines was different in different environments.The yield variation degree of most OsNramp5 gene knockout strains was larger than that of the original varieties,and the fluctuation of yield decrease rate of the OsNramp5 knockout lines in different environments varied with cultivar backgrounds.In addition,there were cases that,different OsNramp5 knockout lines of the same variety background(there were differences in genomic background mutations during tissue culture between lines)and different sister lines of isolated offspring(from a common ancestor line)with the same knockout genotype,had significant differences in yield.The effect of OsNramp5 gene knockout on rice yield was influenced by cultivar type,somatic variation and environment,and the yield stability of most OsNramp5 knockout materials was impaired.Therefore,it is recommended to select suitable varieties for OsNramp5 gene knockout,and carefully select excellent strains or backcross after obtaining gene knockout strains,and carry out multi-year multi-point tests before application.