理解天然橡胶遗传材料之间具有重要性状的变异性和关联性对于有效利用此类材料进行育种至关重要。这项研究的目的是确定用作选择耐旱基因型的指标的九个性状之间的遗传变异性和关联性。测试基因型为RRIM 600，NIG 800，NIG 801，NIG 802，NIG 803，NIG 804，PR 107，RRIM 628，GT I和PB 5/51。观察了十个基因型中的植物高度，叶片数，植物周长，植物活力，植物存活率，叶黄，叶衰老和叶落。从方差分析（ANOVA）获得的结果表明，所有研究的字符均存在显着差异。整个基因型和干旱胁迫时期，株高，叶片数，叶片周长，叶片面积，叶片变黄，叶片衰老和叶片落落表现出高度显着的变化。叶片数量，叶片下降，植物存活率和植物周长的基因型差异相对较高，导致广义遗传力估计值分别较高，分别为0.96、0.82、0.76和0.71。同样，所有性状的高基因型变异系数（GCV）从29％到395％，以及高遗传进展，叶面积从20.98％增长到植物周长的25.55％，叶黄变（34.13％），植物活力（36.16％）和获得了69.98％的叶数。除植物存活率百分比外，所有其他性状之间都具有正相关和显着相关。植物存活率与其他农艺性状之间的负相关关系表明，植物存活率的显着降低将增加农艺性状，例如植物高度，周长和活力。在植物存活率，所需性状和其他农艺特性之间寻求平衡是必要的。
Understanding the variability and the association existing among natural rubber genetic materials for important traits is vital for the effective utilization of such materials for breeding purposes. The aim of this study was to determine the genetic variability and associations among the nine traits used as indices for picking drought tolerant genotypes. The test genotypes were RRIM 600, NIG 800, NIG 801, NIG 802, NIG 803, NIG 804, PR 107, RRIM 628, GT I, and PB 5/51. Observations were made on plant height, number of leaves, plant girth, plant vigor, percentage plant survival, leaf yellowing, leaf senescence and leaf fall among the ten genotypes. Results obtained from the analysis of variance (ANOVA) showed that there were significant variations for all the characters studied. The plant height, number of leaves, plant girth, leaf area, leaf yellowing, leaf senescence and leaf fall, showed highly significant variations across the genotypes and drought stress periods. Genotypic variances were relatively high for number of leaves, leaf fall, plant survival and plant girth leading to high broad sense heritability estimates 0.96, 0.82, 0.76 and 0.71 respectively. Also high genotypic coefficients of variation (GCV) for all the traits from 29% to 395% and high genetic advance at 20.98% in leaf area to 25.55% in plant girth, leaf yellowing (34.13%), plant vigor (36.16%) and 69.98% in number of leaves were obtained. All the traits except percentage plant survival had positive and significant association with each other. The negative correlation between plant survival and other agronomic characters suggests that a considerable decrease in percentage plant survival will increase agronomic traits such as plant height, girth and vigor. Striking a balance between plant survival, also a desired trait and other agronomic characters is necessary.
Key words： Natural rubber Seedlings, genetic variability, correlation analysis, agronomic characters