ISSN 2375-1185
African Journal of Agronomy ISSN 2375-1177 Vol. 8 (9), pp. 001-006, September, 2020. © International Scholars Journals
Full Length Research Paper
The cytological instability of neoallopolyploids suggesting a potent way for DNA introgression: The case of synthetic hexaploid wheat × Aegilops peregrina
Youwei Yang1,2, Lianquan Zhang1,2, Zehong Yan1,2, Youliang Zheng1,2 and Dengcai Liu1,2,3*
1Triticeae Research Institute, Sichuan Agricultural University, Wenjiang, 611130, Sichuan, P. R. China.
2Key Laboratory of Crop Genetic Resources and Improvement, Ministry of Education, Sichuan Agricultural University, Yaan 625014, Sichuan, P. R. China.
3Northwest Plateau Institute of Biology, Chinese Academy of Science, Qinghai 810001, P. R. China.
Accepted 18 August, 2020
Abstract
SHW-L1 is a newly synthetic hexaploid wheat, which has a genomic combination analogous to that of natural common wheat. In the present study, intergeneric F1 hybrids of SHW-L1 - Aegilops peregrina AS24 were produced without embryo rescue. Among the 31 F1 hybrid plants observed, 20 had the expected chromosome number 2n = 35 and were euploids (genome ABDUSl). The remainder 11 plants were aneuploids with 33, 34, 36 and 37 chromosomes, indicating that the neoallohexaploid SHW-L1 was cytologically instable and produced aneuhaploid gametes with 19, 20, 22 and 23 chromosomes, respectively. The hybrid plant lacking chromosome 5B carrying Ph1 showed a very high level of homoeologous chromosome pairing. The absence of Ph gene provides a potent cytological mechanism for DNA introgression among homoeologous chromosomes between newly synthetic wheat and wild species.
Key words: Aneuploids, common wheat, gene flow, neopolyploid, Ph1.