为了解枇杷(Eriobotrya japonica)叶片性状和单果质量的遗传多样性及其相关性,对'宁海白'与'大房'杂交组合的F1群体(123株)的7个叶片性状与单果质量进行相关分析.结果表明,叶片的长度、宽度、厚度和叶柄长度及单果质量5个性状在后代中均呈现连续性较好的正态分布,其中单果质量、叶片的长度、宽度和厚度呈趋小遗传趋势,叶柄长度呈趋中变异趋势.F1杂交群体叶面形态主要以"稍皱"为主,叶片形状以"椭圆形"为主,叶基形状以"楔形"为主.单果质量与叶柄长度、叶片长度、叶片宽度、叶片厚度均表现出极显著的正相关性.因此,叶柄长度可考虑作为早期筛选大果优株的参考指标之一.

Fruit weight is an integral part of fruit quality and directly influences the commodity value and economic return of fruit crops. Despite the importance of fruit weight, its underlying molecular mechanisms remain understudied, especially for perennial fruit tree crops such as cultivated loquat (Eriobotrya japonica Lindl.). Auxin is known to regulate fruit development, but its role and metabolism during the development of loquat fruit remain obscure. In this study, we used a multi-omics approach, integrating whole-genome resequencing-based quantitative trait locus (QTL) mapping with an F1 population, population genomics analysis using germplasm accessions, transcriptome analysis, and metabolic profiling to identify genomic regions potentially associated with fruit weight in loquat. We identified three major loci associated with fruit weight, supported by both QTL mapping and comparative genomic analysis between small- and large-fruited loquat cultivars. Comparison between two genotypes with contrasting fruit weight performance by transcriptomic and metabolic profiling revealed an important role for auxin in the regulation of fruit development, especially at the fruit enlargement stage. The multi-omics approach identified homologs of ETHYLENE INSENSITIVE 4 (EjEIN4) and TORNADO 1 (EjTRN1) as promising candidates for the control of fruit weight. Three single nucleotide polymorphism (SNP) markers were also closely associated with fruit weight. Results from this study provide insights into the genetic and metabolic controls of fruit weight in loquat from multiple perspectives. The candidate genomic regions, genes, and sequence variants will facilitate our understanding of the molecular basis of fruit weight and lay a foundation for future breeding and manipulation of fruit weight in loquat.

[目的]探究枇杷果实重要性状的遗传倾向以及果实性状间的相关关系,以期为枇杷杂交育种的亲本选配提供参考.[方法]对宁海白与大房杂交产生的130株F1杂种后代的7个果实重要性状进行调查以及相关性分析.[结果]调查的7个果实性状均呈正态分布,其中果肉厚度、果实横径、果实质量、果实纵径等4个性状表现出趋低遗传倾向;种子数、种子质量、可溶性固形物含量3个性状表现出趋高遗传倾向.相关性分析显示,果实质量与其他6个性状均呈极显著相关,而通径分析显示,果实横径、种子质量、果肉厚度、果实纵径、种子数是影响果实质量的主要因素,其中果实横径和种子质量对果实质量的影响最大,而种子数的影响最小.[结论]7个果实重要性状均为数量性状,其中果肉厚度、果实横径、果实质量、果实纵径遗传倾向趋于趋低遗传,种子数、种子质量、可溶性固形物含量为趋高遗传;果实横径和种子质量是影响果实质量的关键性状.