The KL system in wheat permits homoeologous crossing over between closely related chromosomes
Chaolan Fan,
Jiangtao Luo,
Jiaojiao Sun,
Hong Chen,
Liqiong Li,
Lanyue Zhang,
Xue Chen,
Yazhou Li,
Shunzong Ning,
Zhongwei Yuan,
Bo Jiang,
Lianquan Zhang,
Xuejiao Chen,
Adam J. Lukaszewski,
Dengcai Liu,
Ming Hao
Affiliations
Chaolan Fan
State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China, Sichuan Agricultural University, Chengdu 611130, Sichuan, China; Department of Botany and Plant Sciences, University of California, Riverside, CA 92521, USA; Triticeae Research Institute, Sichuan Agricultural University, Chengdu 611130, Sichuan, China
Jiangtao Luo
Crop Research Institute, Sichuan Academic of Agricultural Science, Chengdu 610066, Sichuan, China
Jiaojiao Sun
Triticeae Research Institute, Sichuan Agricultural University, Chengdu 611130, Sichuan, China
Hong Chen
Triticeae Research Institute, Sichuan Agricultural University, Chengdu 611130, Sichuan, China
Liqiong Li
Triticeae Research Institute, Sichuan Agricultural University, Chengdu 611130, Sichuan, China
Lanyue Zhang
Triticeae Research Institute, Sichuan Agricultural University, Chengdu 611130, Sichuan, China
Xue Chen
Triticeae Research Institute, Sichuan Agricultural University, Chengdu 611130, Sichuan, China
Yazhou Li
State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China, Sichuan Agricultural University, Chengdu 611130, Sichuan, China
Shunzong Ning
Triticeae Research Institute, Sichuan Agricultural University, Chengdu 611130, Sichuan, China
Zhongwei Yuan
Triticeae Research Institute, Sichuan Agricultural University, Chengdu 611130, Sichuan, China
Bo Jiang
Triticeae Research Institute, Sichuan Agricultural University, Chengdu 611130, Sichuan, China
Lianquan Zhang
State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China, Sichuan Agricultural University, Chengdu 611130, Sichuan, China
Xuejiao Chen
Triticeae Research Institute, Sichuan Agricultural University, Chengdu 611130, Sichuan, China
Adam J. Lukaszewski
Department of Botany and Plant Sciences, University of California, Riverside, CA 92521, USA; Corresponding authors
Dengcai Liu
State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China, Sichuan Agricultural University, Chengdu 611130, Sichuan, China; Triticeae Research Institute, Sichuan Agricultural University, Chengdu 611130, Sichuan, China; Corresponding authors
Ming Hao
State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China, Sichuan Agricultural University, Chengdu 611130, Sichuan, China; Corresponding authors
The Chinese wheat landrace Kaixianluohanmai (KL) expresses the ph-like phenotype. A major QTL, QPh.sicau-3A (syn. phKL), responsible for this effect has been mapped to chromosome arm 3AL. This study presents some characteristics of homoeologous pairing and recombination induced by phKL. In KL haploids, the level of homoeologous pairing was elevated relative to Ph1 Chinese Spring (CS) haploids. There was a clear preference for A–D pairing and less frequent for A–B and B–D, reflecting the higher levels of affinity between genomes A and D in wheat. The characteristics of pairing were affected by temperature and magnesium ion supplementation. The suitability of phKL for chromosome engineering was tested on three pairs of homoeologues: 2Sv-2B, 2Sv-2D, and 2RL-2BL. The recombination rates were 1.68%, 0.17%, and 0%, respectively. The phKL locus in KL induced a moderate level of homoeologous chromosome pairing and recombination when the Ph1 locus of wheat was present, both in wheat haploids and hexaploids. The Ph1-imposed criteria for chromosome pairing and crossing over were relaxed to some degree, permitting homoeologous crossing over but only between closely related chromosomes; there was no crossing over between more differentiated chromosomes. Therefore, the phKL system (QPh.sicau-3A) can be a useful tool in chromosome engineering of wheat to transfer genes from closely related species with the benefit of reduced genomic chaos generated by the ph1b mutation.
