酸性红壤区耐低钙花生种质资源的筛选

Screening of Peanut Germplasm Resources Resistant to Low Calcium in Acid Red Soil Area

为筛选耐低钙种质,有效利用酸性红壤,扩大花生种植面积,在南方地区典型酸性低钙土壤(pH值5.44,交换性钙376.0 mg/kg,水溶性钙11.2 mg/kg),采用大田试验研究了不施钙和施钙(CaO)750 kg/hm^(2)处理对105份不同地域来源花生种质资源的形态性状、叶绿素含量(SPAD值)、产量及其构成因子等24项指标及其耐低钙系数的影响。结果表明:与施钙相比,不施钙处理花生出苗率、SPAD值、荚果产量、单株饱果数、单株总果数、出仁率、荚果饱满度及籽仁品质等均有不同程度降低,其中荚果产量和空果率差异达到显著水平。通过主成分分析,可以将24项评价指标的耐低钙系数降维为8个主成分,累计贡献率为78.001%,对各主成分的贡献率大小以单株产量(26.396%)和饱果数率(24.951%)最高,表明不施钙单株产量和饱果数率最能代表不同花生品种对低钙的响应状况。以花生相对产量和产量耐低钙系数为特征变量,通过聚类分析可将105个品种的耐低钙性划分为5个等级:极强耐低钙、强耐低钙、中度耐低钙、敏感和高敏感,各类型所占品种比例分别为1.90%,0.95%,18.10%,78.10%,0.95%,说明我国绝大部分花生种质资源对低钙敏感,但也存在极强和强耐种质,这为开展耐低钙生态育种奠定了良好种质资源基础。

Screening low calcium tolerant germplasm is of great significance for the effective utilization of acid red soil and the expansion of peanut planting area.A field experiment was conducted to study the effects of application of 750 kg/ha calcium fertilizer(CaO)and no application of calcium fertilizer(CK)on 24 indexes including morphological traits,chlorophyll content(SPAD),yield and its components and low calcium tolerance coefficient of 105 peanut germplasm resources from different regions in typical acid low calcium soil(pH 5.44,exchangeable calcium 376.0 mg/kg,water-soluble calcium 11.2 mg/kg)in Southern China.The results showed that:compared with calcium application,peanut seedling emergence rate,SPAD value,pod yield,full fruit number per plant,total fruit number per plant,kernel rate,pod plumpness and kernel quality were decreased in different degrees under natural low calcium treatment,in which pod yield and empty fruit rate were significantly different.Through principal component analysis,the low calcium tolerance coefficient of 24 evaluation indexes could be reduced to 8 principal components,with a cumulative contribution rate of 78.001%.The contribution rate of each principal component was the highest in yield per plant(26.396%)and full fruit rate(24.951%),indicating that the yield per plant and full fruit rate could best represent the response of different peanut varieties to low calcium under low calcium acid conditions.Taking the relative yield and low calcium tolerance coefficient of peanut as characteristic variables,the low calcium tolerance of 105 peanut varieties could be divided into five grades by cluster analysis:extremely strong low calcium tolerance,strong low calcium tolerance,moderate low calcium tolerance,sensitive and high sensitive.The proportion of each type of peanut varieties was 1.90%,0.95%,18.10%,78.10% and 0.95% respectively,indicating that most peanut germplasm resources in China were sensitive to low calcium,however,there are also extremely strong and strong tolerant germplasm,which laid a good foundation for carrying out ecological breeding of low calcium tolerance.