Abstract:
CONCLUSIONS: Genetic improvement of seed yield and drought resistance could be simultaneously gained in anise when breeding for drought resistance. Improving the water use efficiency of anise is a primary objective of anise breeding programs aimed at mitigating the impacts of drought stress. This study aimed to determine the predominant mechanisms involved in drought tolerance and investigate the genetic control of associated traits with drought tolerance and higher grain yield. According to these aims, 10 half-diallel hybrids and their five parents were evaluated in both field and greenhouse lysimetric experiments under well-watered and water deficit stress conditions. The results indicated that the inheritance of grain yield is complex and affected by water deficit stress. Similar heritability and genetic architecture were detected for flowering time and percentages of photosynthate partitioned to grain (PPPG) in both well-watered and water deficit stress treatments. Significant negative genetic correlations were observed between grain yield and flowering time, root dry mass, root diameter, root volume, root number, percentages of photosynthate partitioned to shoot, and percentages of photosynthate partitioned to root. Therefore, the selection of low values of these attributes can be used to improve grain yield under drought conditions. In contrast, a positive significant genetic linkage between grain yield and PPPG, chlorophyll content, cell membrane stability, and leaf relative water content reveal selection for high values of these attributes is favored. These attributes could be used as surrogate selection criteria in the early segregating generations. The P1 parent (early ripening parent) contained key genes associated with PPPG and drought escape. It was concluded that improvement of drought tolerance and grain yield could be simultaneously achieved in anise breeding programs.
摘要:
结论:茴香在抗旱性育种中可以同时获得种子产量和抗旱性的遗传改良。提高茴香的水分利用效率是茴香育种计划的主要目标,该计划旨在减轻干旱胁迫的影响。本研究旨在确定耐旱性的主要机制,并研究与耐旱性和较高谷物产量相关性状的遗传控制。根据这些目标,在水分充足和水分亏缺的胁迫条件下,在田间和温室测压实验中评估了10个半透析杂种及其五个亲本。结果表明,籽粒产量的遗传是复杂的,受水分亏缺胁迫的影响。在充分浇水和缺水胁迫处理中,开花时间和分配到谷物(PPPG)的光合产物百分比均检测到相似的遗传力和遗传结构。籽粒产量和开花时间之间存在显著的负遗传相关,根干质量,根部直径,根体积,根号,分配到芽的光合产物的百分比,和分配到根的光合产物的百分比。因此,选择这些属性的低值可用于提高干旱条件下的谷物产量。相比之下,谷物产量和PPPG之间存在显著的正遗传连锁,叶绿素含量,细胞膜稳定性,和叶片相对含水量表明选择这些属性的高值是有利的。这些属性可以用作早期分离世代的替代选择标准。P1亲本(早熟亲本)包含与PPPG和干旱逃逸相关的关键基因。结论是,在茴香育种计划中可以同时提高耐旱性和谷物产量。