磷胁迫下不同基因型大豆苗期根系形态及生物量的差异

Study on Variation in Characteristics of Phosphorus Efficiency among Different Soybean Genotypes at Seedling Stage under Phosphorus Stress

在磷胁迫[0mmol/L(P),砂培]条件下,对不同基因型大豆苗期在根系形态、生物量等方面的差异进行了研究,结果表明:磷高效基因型在两叶期并未发挥出其基因型潜力的优势;四叶期,磷高效基因型的侧根数、侧根长、根系吸收面积、茎叶干重等性状的受抑制程度均显著低于磷中、低效基因型,而地下干重、根冠比却受到了较中、低效基因型更强的诱导作用。综合评价表明,磷高效基因型的综合值(评价磷效率特性的综合指标)显著高于磷中、低效基因型,显示出了较强的抗磷胁迫能力,但磷高效基因型并非所有性状都表现突出;四叶期可作为大豆耐低磷胁迫的筛选期,根表面积和活跃吸收面积可作为衡量磷效率特性的特异性指标。

Under the condition [0mmol/L(P),raise in vermiculite] of phosphorus stress, variation in root morphology and biomass among different soybean genotypes at seedling stage were studied, the result shows: At two-leaf age, higher P-efficiency genotypes(K1 and K2) don't develop their potential advantages; at four-leaf age, some characteristics of K1 and K2, such as lateral root number, lateral root length, root absorbent area and dry weight of shoot are all less reduced than those of intermediate P-efficiency genotypes(Z1 and Z2) and of lower P-efficiency genotypes(M1 and M2), and dry weight of root and R/S of higher P-efficiency genotypes are more increased than those of the others. The comprehensive evaluation indicates that comprehensive value (comprehensive index of evaluating characteristics of P-efficiency) of K1 and K2 are both larger significantly than those of Z1 and Z2 and of M1 and M2, it shows that K1 and K2 have stronger capability of tolerance to P deficiency than the other genotypes. But it is not true that all characteristics of higher P-efficiency genotypes have an advantage over intermediate P-efficiency and lower P-efficiency genotypes; root surface area and active absorption area can be used to evaluate characteristics of P efficiency, and four-leaf age is the right age to screen soybean genotypes with tolerance to P deficiency.