背景:在柑橘物种中,柠檬(CitruslimonBurmf。)是受两点蜘蛛螨(TetranychusurticaeKoch)影响最大的动物之一。此外,化学控制受到螨对杀螨剂产生遗传抗性的能力的阻碍。在这种情况下,鉴定宿主抗性的遗传基础可以代表控制蜘蛛螨的可持续策略。在本研究中,使用关联作图方法对柠檬种群进行了标记-性状关联分析。通过在改良的Huffaker细胞中进行的离叶测定,对由109个种质组成的特异性全同胞种群进行了表型分析。那些人,补充了两个不同物种间的隔离种群,使用称为SPET(单引物富集技术)的靶测序方法进行基因分型,所产生的SNP用于产生整合的遗传图谱。
结果:全同胞人口中受损面积的百分比显示出定量分布,数值范围为0.36%至9.67%。总共选择了47,298个SNP进行关联作图研究,并且在连锁组5上检测到与蜘蛛螨抗性相关的显着标记。QTL区间的硅基因注释使得能够检测到13个参与对生物和非生物胁迫的免疫应答的基因。基因表达分析表明,编码乙烯反应转录因子ERF098样的基因过度表达,已经在拟南芥和水稻中以参与防御反应为特征。
结论:鉴定与抗蜘蛛螨攻击相关的分子标记可以为开发标记辅助育种计划铺平道路,以开发新型选择耦合有利的农艺性状(例如,果实品质,产量)对螨具有较高的抗性。
BACKGROUND: Among the Citrus species, lemon (Citrus limon Burm f.) is one of the most affected by the two-spotted spider mite (Tetranychus urticae Koch). Moreover, chemical control is hampered by the mite\'s ability to develop genetic resistance against acaricides. In this context, the identification of the genetic basis of the host resistance could represent a sustainable strategy for spider mite control. In the present study, a marker-trait association analysis was performed on a lemon population employing an association mapping approach. An inter-specific full-sib population composed of 109 accessions was phenotyped through a detached-leaf assays performed in modified Huffaker cells. Those individuals, complemented with two inter-specific segregating populations, were genotyped using a target-sequencing approach called SPET (Single Primer Enrichment Technology), the resulting SNPs were employed for the generation of an integrated genetic map.
RESULTS: The percentage of damaged area in the full-sib population showed a quantitative distribution with values ranging from 0.36 to 9.67%. A total of 47,298 SNPs were selected for an association mapping study and a significant marker linked with resistance to spider mite was detected on linkage group 5. In silico gene annotation of the QTL interval enabled the detection of 13 genes involved in immune response to biotic and abiotic stress. Gene expression analysis showed an over expression of the gene encoding for the ethylene-responsive transcription factor ERF098-like, already characterized in Arabidopsis and in rice for its involvement in defense response.
CONCLUSIONS: The identification of a molecular marker linked to the resistance to spider mite attack can pave the way for the development of marker-assisted breeding plan for the development of novel selection coupling favorable agronomical traits (e.g. fruit quality, yield) with a higher resistance toward the mite.