豫谷1号和青狗尾草RIL群体根系变异和垂直分布

根系在谷子生长发育过程中起着极为重要的作用。本试验以豫谷1号和青狗尾草杂交衍生的RIL群体196个家系为材料, 采用根管土柱栽培实测根系性状的方法, 调查谷子根系性状的变异及在土壤中垂直空间的分布情况。结果表明, 谷子单株根系长度平均为(89.42±32.67) m, 单株根系总面积平均为(2.74±0.93) dm², 单株根系总体积平均为(30.94±13.93) mL, 单株根系根直径平均数为(0.52±0.06) mm, 单株根系平均干重为(0.98±0.45) g, 除根系直径外, 各根系性状在家系间均表现很高的变异系数; 单株根量垂直分布分析表明, 谷子根深可到2.4 m, 90%的根量分布在0~200 cm范围之内, 根量在土壤中整体分布呈“8”型架构; 根系性状和地上农艺性状的相关分析表明, 单株地上生物量和单株籽粒产量与地下根量呈极显著正相关, 是根系选择的间接指标。

Phenotype Variation and Vertical Distribution of Foxtail Millet Root System in RIL from a Cross of Yugu 1× Wild Green Foxtail W53

Foxtail millet is a well-known drought tolerant crop in arid and semi-arid regions, because root system plays an essential role in crop growth period. Taking 196 lines from foxtail millet RIL, derived from a cross of cultivar Yugu 1 ´ wild green foxtail W53 as materials, we investigated root system variance and distribution in the soil with the root canal soil column culture. The results showed that the average length of root per plant, the average root surface area per plant, the average root volume per plant, the average root diameter per plant and that of root dry weight per plant were 89.42 ± 32.67 m, 2.74 ± 0.93 dm², 30.94 ± 13.93 mL, 0.52 ± 0.06 mm, and 0.98 ± 0.45 g, respectively. There existed high variation coefficients in the root characters of all lines except root diameter. The deepest root system was detected in 2.4 meters beneath the soil surface, and 90% of root biomass of foxtail millet distributed from the soil surface to the depth of 200 centimeters. The overall distribution of foxtail millet root system was a “8” type structure, which means that foxtail millet root biomass gradually decreased from the soil surface to a depth of 60 centimeters, increased slightly from soil layer of 60 centimeters to 100 centimeters, and then decreased again to zero in the deeper soil layer. The correlation analysis of root traits and agronomic traits above ground showed that plant straw weight and plant grain yield were positively correlated with root traits and the correlation coefficients could be used an indirect index for germplasm evaluation and breeding selection.