摘要
[目的]选育磷高效水稻材料是利用土壤磷资源的有效方式,根系是水稻吸收磷素最重要的器官,其形态结构特征直接影响水稻的磷素吸收能力,研究水稻根系发育特征有助于揭示其磷高效吸收的机理.[方法]采用水培试验,以 40 份水稻材料为研究对象,设置 0.003 mmol/L(低磷)和 0.3 mmol/L(正常磷)两个供磷处理,于分蘖期调查水稻地上部生物量和磷积累量,采用聚类分析筛选磷高效水稻材料.针对筛选获得的磷高效水稻材料R527 和磷低效水稻材料IR58025,分析其根系形态和解剖结构特征,解析水稻根系发育特征与磷吸收的关系.[结果]1)低磷条件下,40 份水稻材料磷吸收能力存在显著差异,生物量和磷积累量的范围分别为 0.11～0.93 g/plant和 0.07～0.58 mg/plant.以磷积累量为主、生物量为辅进行聚类分析,获得磷高效水稻材料R527 和磷低效水稻材料IR58025.2)低磷条件下,磷高效水稻材料R527 的生物量(0.83 g/plant)和磷积累量(0.46 mg/plant)显著高于磷低效水稻材料IR58025,分别为IR58025 的 6.38 和 5.75 倍.3)低磷条件下,磷高效水稻材料R527 的总根长、根表面积、不定根长、侧根长和侧根表面积比正常磷处理分别增加了 61.79%、38.12%、60.44%、67.99%和 186.67%.低磷条件下,磷高效水稻材料R527 的总根长、根表面积、根体积、平均根直径、不定根长、侧根长、不定根表面积和侧根表面积分别为磷低效水稻材料IR58025 的 2.62、2.87、3.22、1.18、4.41、2.97、3.97 和 1.45 倍.4)低磷条件下,磷高效水稻材料R527 中柱、外皮层和皮层占比分别为磷低效水稻材料IR58025 的 1.11、0.67 和 1.05 倍.5)低磷条件下,水稻的总根长、根表面积、根体积、平均根直径、不定根长、侧根长、不定根表面积、侧根表面积、皮层占比和中柱占比与生物量和磷积累量显著正相关,外皮层和内皮层占比与生物量和磷积累量显著负相关.[结论]磷高效水稻材料R527 的生物量和磷积累量均显著高于磷低效水稻材料IR58025.低磷条件下,磷高效水稻材料R527 更大的总根长、根表面积、根体积、不定根长、侧根长、不定根表面积、侧根表面积和皮层占比,更低的外皮层和内皮层占比是其磷高效吸收的重要原因.
Abstract
[Objectives]Breeding rice materials with high phosphorus(P)uptake efficiency is an effective way to use the soil P resources.Rice root is the most important organ for P absorption and studying the root morphological and structural characteristics can reveal the mechanisms of P-efficient uptake.[Methods]A hydroponic experiment was conducted with 40 rice materials under low P(0.003 mmol/L)and normal P(0.3 mmol/L)treatment,and the rice plants were sampled at the tillering stage for determination of shoot biomass and P concentration.Through cluster analysis of shoot P accumulation and biomass,R527 and IR58025 were identified as high-P efficiency and low-P efficiency materials,respectively.The root morphology,and root anatomical structure of the two rice materials were further determined to elucidate the relationship between rice root development characteristics and P uptake.[Results]1)Under low P conditions,the 40 rice materials showed significantly different biomass and P accumulation,ranging from 0.11 to 0.93 g/plant in biomass and 0.07 to 0.58 mg/plant in P accumulation,with coefficients of variation of 49.41%and 49.55%,respectively.2)Under low P conditions,the biomass(0.83 g/plant)and P accumulation(0.46 mg/plant)of R527 were 6.38 and 5.75 times higher than those of IR58025.3)The total root length,root surface area,adventitious root length,lateral root length,and lateral root surface area of R527 under low P conditions was 61.79%,38.12%,60.44%,67.99%and 186.67%higher than under normal P conditions.And the total root length,root surface area,root volume,average root diameter,adventitious root length,lateral root length,adventitious root surface area and lateral root surface area of R527 under low P stress were 2.62,2.87,3.22,1.18,4.41,2.97,3.97 and 1.45 times of those in IR58025.4)Under low P conditions,the proportions of stele,epidermis,cortex in R527 were 1.11,0.67 and 1.05 times of those in IR58025.5)Under low P conditions,total root length,root surface area,root volume,average root diameter,adventitious root length,adventitious root surface area,lateral root length,lateral root surface area,cortex proportion,and stele proportion of rice showed positive correlation with biomass and P accumulation,while epidermis and endodermis proportions showed negative correlation.[Conclusions]The growth of high-P efficiency rice material R527 is less inhibited than low-P efficiency material IR58025 under low P conditions,due to the significantly higher biomass and P accumulation.Under low P conditions,R527 could develop large total root length,root surface area,root volume,adventitious root length,lateral root length,adventitious root surface area,lateral root surface area,and cortex proportion,as well as lower epidermis and endodermis proportions,which is contributed to its efficient P uptake.
基金项目
西南作物基因资源发掘与利用国家重点实验室"生物育种"揭榜挂帅重点开放课题(SKL-KF202213)
四川省自然科学基金青年科学基金(2022NSFSC1664)
国家科技期刊平台
NSTL
万方数据