镉低积累优质常规稻韶香100的培育及试验示范

Breeding and Experimental Demonstration of Cadmium Low Accumulation High Quality Conventional Rice Shaoxiang 100

通过重离子诱变香型优质稻材料44-5,结合M1TDS技术,培育出Os NRAMP5基因突变镉低积累水稻韶香100。2021-2023年韶香100在湖南多地进行了试验示范,并参加国家镉低积累品种自主试验。Os NRAMP5基因突变降镉(Cd)的同时锰(Mn)的积累也显著降低,而Mn是植物生长必须的微量元素。本研究比较了韶香100及其原始品系44-5的籽粒镉积累特性、产量、品质及低温耐受性等。研究结果表明:韶香100在多地试验示范中表现出稳定的稻谷镉低积累特性,植株Mn的积累下降,但产量相比原始品系44-5无显著差异,除株高外,其他主要农艺性状也无明显差异。随着播期推迟,韶香100与原始品系44-5结实率均明显下降,相对耐冷系数和品种耐冷指数分别为0.75和0.75,47.2%和49.2%,孕穗期低温耐受性均为4级(敏冷)。韶香100相比原始品系44-5并未因Os NRAMP5基因突变引起植株Mn积累降低而造成低温耐受性下降,鉴定结果表明两者都是耐冷性一般的品种。鉴于此,韶香100在湖南、江西作为双季晚稻种植时,建议适时早播,避免生长后期因低温胁迫造成产量损失。

The rice variety Shaoxiang100 with low cadmium accumulation was developed through heavyion mutagenesis of the aromatic high-quality rice material 44-5,through applying the M1TDS technology and the mutation of the OsNRAMP5 gene.The variety Shaoxiang100 underwent multi-location testing in Hunan province from 2021 to 2023,and has also been part of national independent trials for varieties with low cadmium(Cd)accumulation.The mutation of the OsNRAMP5 gene reduces Cd accumulation,and also manganese(Mn),which is essential for plant growth.This study investigated the Cd accumulation characteristics,yield,quality,and low-temperature tolerance of Shaoxiang100 and its original strain 44-5.These multi-location experiments revealed that Shaoxiang 100 exhibited stable,low levels of Cd in rice grains,with a reduced accumulation of Mn in plants.However,no significant difference was observed in yield when compared to the original variety,44-5.For main agronomic traits,except for plant height,no significant difference was detected.Both Shaoxiang 100 and the original line 44-5 exhibited a significant decrease in fruiting rate when delay sowing applied.However,late sowing didn’t affect yield or other main agronomic traits,except for plant height.Additionally,the relative cold tolerance coefficient and variety cold tolerance index were 0.75 and 0.75,respectively,indicating a decrease of 47.2%and 49.2%.The low-temperature tolerance at the spikelet stage was classified as level 4,indicating sensitivity to cold.Compared to the original strain 44-5,Shaoxiang 100 did not show a decrease in Mn accumulation or low-temperature tolerance.Both strains were found to have general cold tolerance.Collectively,it is recommended that Shaoxiang 100 as double-crop late rice,can be planted in Hunan and Jiangxi to prevent yield loss from low-temperature stress during the late growth period.