Guar [Cyamopsis tetragonoloba (L.) Taub] is a legume grown worldwide, tolerant of hot, dry, and saline conditions. Phenotyping is a key bottleneck in guar improvement, with belowground root nodule phenes being largely overlooked. To address this bottleneck, a greenhouse study was conducted to evaluate phenotypic variability and associations in 14 nodule and plant growth parameters in 50 guar genotypes over 48 days. Nodule mass per plant differed among genotypes and had moderate heritability (P = 0.011, H² = 0.40), while nodule number did not differ and had low heritability (P = 0.247, H² = 0.14), and the parameters were not correlated. Nodule mass was correlated with total plant N (r = 0.56), plus most biomass parameters, indicating phenotypic links between plant capacity to support nodulation, N₂ accumulation, and plant biomass production. Stem diameter may be useful as an indirect, high-throughput selection trait for increased nodulation in guar, as there was a positive association between stem diameter and nodule mass. Branch number and stem diameter, which have great agronomic significance, had wide phenotypic variability and were highly heritable. Reproductive development was delayed in branched genotypes, which may have implications in breeding guar for environments that differ in growing season length. Despite low heritability, there was a wide range in specific leaf area (SLA) that may be exploited by breeders to optimize drought tolerance and N use efficiency traits. These analyses give novel and confirmatory insights on the nature and associations of phenotypic character traits in guar, particularly nodule traits, providing added tools for breeders in developing desired and beneficial plant ideotypes.

瓜尔豆[ Cyamopsis tetragonoloba (L.) Taub] 是一种全球种植的豆科植物，可耐受炎热、干燥和盐碱环境。表型分析是瓜尔胶改良的关键瓶颈，地下根瘤现象在很大程度上被忽视。为了解决这个瓶颈，进行了一项温室研究，以评估 48 天内 50 种瓜尔胶基因型的 14 个根瘤和植物生长参数的表型变异性和关联。单株根瘤质量在基因型之间存在差异，具有中等遗传力（P = 0.011，H ² = 0.40），而根瘤数没有差异且具有低遗传力（P = 0.247，H ² = 0.14），并且参数不相关。根瘤质量与植物总氮相关（r = 0.56)，加上大多数生物量参数，表明植物支持结瘤的能力之间的表型联系，N ₂积累和植物生物量生产。茎直径可以作为一种间接的、高通量的选择特性，用于增加瓜尔豆中的结瘤，因为茎直径和结瘤质量之间存在正相关。具有重要农艺意义的分枝数和茎粗具有广泛的表型变异性和高度遗传性。分枝基因型的生殖发育延迟，这可能对在生长季节长度不同的环境中培育瓜尔胶产生影响。尽管遗传力低，但育种者可以利用特定叶面积 (SLA) 来优化耐旱性和氮利用效率性状的范围很广。这些分析为瓜尔豆表型特征的性质和关联提供了新的和确凿的见解，特别是根瘤性状，