Onion is a highly cross-pollinated crop, high variability could possibly come from traditional seed production by out-crossing or by open pollination and it could lead to more diversity and variation. The high phenotypic, genotypic variation coefficients reveal high-quantifiable variation of traits in S1 lines. Selection of lowest premature bolting and split bulbs producing genotypes, least incidence of purple blotch incidence and thrips incidence with the highest weight of ten bulbs and maximum plot yielding genotypes were more appropriate for genetic improvement of onion. The traits aided the yield witnessed high traits heritability (h2) and maximum genetic-advance-mean (GAM) and isolation of S1 lines in terms of selection indices fixed for higher values of measurement. Whereas traits like premature bolting, split bulbs, purple blotch incidence, thrips incidence and were selected at least values although these traits were high heritability (h2) and GAM could contribute for additive-gene-action and hence it indicates the straight mass selection be more effective for genetic improvement of onion genotypes or lines. The genetic distance was highly flanked by Cluster-II and –IV groups and was highly divergent. Hence, the selection of parental lines from these groups is more appropriate for traditional heterosis breeding.

中文翻译：

---

洋葱自交系（S1）之间的变异性和遗传多样性

洋葱是高度异花授粉的作物，高变异性可能来自传统种子生产的异源杂交或开放授粉，并且可能导致更多的多样性和变异。高表型，基因型变异系数表明S1品系性状的高量化变异。选择产生基因型的最低过早抽穗和分裂鳞茎，紫色斑点和蓟马的发生率最低，十个鳞茎的重量最高，产生最大积果的基因型更适合洋葱的遗传改良。这些性状有助于提高产量，表现出较高的性状遗传力（h2）和最大遗传前均值（GAM）以及S1系的分离，这些选择系针对较高的测量值进行了固定的选择指数。而诸如过早的抽ing，鳞茎裂开，紫斑发生率等特征，尽管这些性状具有很高的遗传力（h2），并且GAM可能有助于加成基因的作用，但蓟马的发病率至少被选择了一些值，因此表明直接选择质量对洋葱基因型或品系的遗传改良更为有效。遗传距离在Cluster-II和-IV组之间高度相邻，并且高度不同。因此，从这些群体中选择亲本系更适合传统的杂种优势育种。