QTL mapping and candidate gene mining of seed size and seed weight in castor plant (Ricinus communis L.)

• Published in: BMC plant biology 2024-09, Vol.24 (1), p.885-15, Article 885
• Main Authors: Huang, Guanrong, Lu, Jiannong, Yin, Xuegui, Zhang, Liuqin, Liu, Chaoyu, Zhang, Xiaoxiao, Lin, Haihong, Zuo, Jinying
• Format: Article
• Language: English
• Subjects: Agricultural research; Candidate gene; Castor (Ricinus communis L.); Castor beans; Castor oil plant; Chemical industry; Chromosome Mapping; Chromosomes; Clusters; Confidence intervals; Gene mapping; Genes; Genes, Plant; Genetic aspects; Genetic structure; Industrial crops; Intervals; Kinases; Mapping; Marker enrichment; Methods; Mining; Phenotype; Phenotypic variations; Physiological aspects; Polymerase chain reaction; Populations; Proteins; QTL analysis; Quantitative trait loci; Quantitative Trait Loci - genetics; Ricinus - genetics; Ricinus communis; Ricinus communis - genetics; Ricinus communis - growth & development; Seed size; Seed weight; Seeds; Seeds - anatomy & histology; Seeds - genetics; Seeds - growth & development; Software; Weight; Weight (Physics)
• ISSN: 1471-2229; 1471-2229
• DOI: 10.1186/s12870-024-05611-6

Castor (Ricinus communis L., 2n = 2x = 20) is an important industrial crop, due to its oil is very important to the global special chemical industry. Seed size and seed weight are fundamentally important in determining castor yield, while little is known about it. In this study, QTL analysis and candidate gene mining of castor seed size and seed weight were conducted with composite interval mapping (CIM), inclusive composite interval mapping (ICIM) and marker enrichment strategy in 4 populations, i.e., populations F , BC , S -1 and S -2, derived from 2 accessions with significant phenotypic differences. In the QTL primary mapping, 2 novel QTL clusters were detected in marker intervals RCM520-RCM76 and RCM915-RCM950. In order to verify their accuracy and to narrow their intervals, QTL remapping was carried out in populations F and BC . Among them, 44 and 30 QTLs underlying seed size and seed weight were detected in F population using methods CIM and ICIM-ADD respectively, including 4-9 and 3-5 ones conferring each trait were identified with a phenotypic variation explained ranged from 37.92 to 115.81% and 32.86-45.98% respectively. The remapping results in BC population were consistent with those in F population. Importantly, 3 QTL clusters (i.e. QTL-cluster1, QTL-cluster2 and QTL-cluster3) were found in marker intervals RCM74-RCM76 (37.1 kb), RCM930-RCM950 (259.8 kb) and RCM918-RCM920 (172.9 kb) respectively; in addition, all of them were detected again, the former one was found in the S -2 population, and the latter two were found simultaneously in the populations S -1 and S -2. Finally, 6 candidate genes (i.e. LOC8266555, LOC8281168, LOC8281151, LOC8259066, LOC8258591 and LOC8270077) were screened in the above QTL clusters, they were differentially expressed in multiple seed tissues of both parents, signifying the potential role in regulating seed size and seed weight. The above results not only provide new insights into the genetic structure of seed size and seed weight in castor, but also lay the foundation for the functional identification of these candidate genes.