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在根袋土培盆栽条件下,以磷高效基因型DH110+、DH147和低效基因型DH49大麦为试验材料,利用根系分析系统分析不同施磷(P2O5)水平(极低磷25 mg·kg-1、低磷50mg·kg-1和正常磷75 mg·kg-1)下,磷高效基因型大麦的根系形态特征及其与植株磷素吸收的关系.结果表明:低磷胁迫显著降低大麦生物量和磷吸收量,其中磷高效基因型的生物量和磷吸收量在各施磷水平下分别为低效基因型的1.24~1.70和1.18~1.83倍;大麦的总根长、总根表面积、平均根系直径、不定根长及其根表面积、侧根长及其根表面积均随施磷水平的降低而显著降低,其中磷高效基因型大麦在各施磷水平下的总根长、总根表面积、比根长、侧根长及根表面积分别为低效基因型的1.46~2.06、1.12~1.51、1.35~1.72、1.69~2.42和1.40~1.78倍,而平均根系直径为低效基因型的70.6%~90.2%;主成分分析表明,平均根系直径、比根表面积和比根长受基因型差异的影响较为明显,是区分两类磷效率基因型大麦根系形态差异的主要指标;偏最小二乘回归分析表明,各施磷水平下,总根长、总根表面积对大麦植株磷素吸收贡献均较大,随施磷水平降低,不定根长、不定根表面积对大麦植株磷素吸收的贡献明显降低,而平均根系直径、比根长、侧根长及其根表面积的贡献明显增加.磷高效基因型大麦可通过维持侧根的生长、根细度和比根长的增加来适应低磷胁迫.
Under the conditions of rhizophere soil culture and pot cultivation, the phosphorus-efficient genotypes DH110 +, DH147 and the inefficient genotype DH49 barley were used as materials to analyze the effects of different phosphorus (P2O5) levels (25 mg · kg-1 , Low phosphorus (50 mg · kg-1) and normal phosphorus (75 mg · kg-1), the root morphological characteristics of barley with phosphorus-efficient genotype and its relationship with plant phosphorus uptake were studied.The results showed that low phosphorus stress significantly reduced barley biomass And phosphorus uptake respectively. The biomass and phosphorus uptake of phosphorus-efficient genotypes were 1.24-1.70 and 1.18-1.83 times of low-efficiency genotypes at each phosphorus application level. The total root length, total root surface area, Root diameter, adventitious root length and root surface area, lateral root length and root surface area decreased significantly with the decrease of phosphorus application. The total root length, total root surface area and specific root area of P efficient genotype barley The length, lateral root length and root surface area were 1.46 ~ 2.06, 1.12 ~ 1.51, 1.35 ~ 1.72, 1.69 ~ 2.42 and 1.40 ~ 1.78 times respectively, while the average root diameter was 70.6% ~ 90.2% of the inefficient genotype. Principal component analysis showed that the average root diameter, specific root surface area and specific root The genotype differences affected more obviously, which was the main index to distinguish the morphological differences between two types of genotypes of barley. Partial least-squares regression analysis showed that total phosphorus content, The contribution of total nitrogen uptake was larger, with the decrease of phosphorus application, the adventitious root length and adventitious root surface area significantly reduced the contribution of barley plant P absorption, while the average root diameter, specific root length, lateral root length and root surface area increased significantly. Highly efficient genotype barley can adapt to low-P stress by maintaining the growth of lateral roots, root fineness and root length.