Inducement and identification of chromosome introgression and translocation of Gossypium australe on Gossypium hirsutum

Abstract

BackgroundWe previously reported the development of a set of Gossypium hirsutum-G. australe alien chromosome addition lines. Naturally, however, G. hirsutum-G. australe chromosome exchanges were very limited, impeding the stable transference of useful genes from G. australe (G2G2 genome) into the most cultivated cotton, G. hirsutum (AADD).ResultsIn the present report, the pollen from a pentaploid (2n = AADDG2) of G. hirsutum-G. australe was irradiated with seven different doses ranging from 10 to 40 Grays and used to pollinate emasculated flowers of G. hirsutum over three consecutive years. Irradiation greatly increased the genetic recombination rates of the G. hirsutum and G. australe chromosomes and a total of 107 chromosome introgression individuals in 192 GISH-negative (with no GISH signal on chromosome) survived individuals, 11 chromosome translocation individuals (containing 12 chromosome translocation events) and 67 chromosome addition individuals were obtained in 70 GISH-positive (with GISH signal(s) on chromosome(s)) survived individuals, which are invaluable for mining desirable genes from G. australe. Multicolor genomic in situ hybridization results showed that there were three types of translocation, whole arm translocation, large alien segment translocation and small alien segment translocation, and that all translocations occurred between the G2-genome and the A-subgenome chromosomes in G. hirsutum. We also found that higher doses induced much higher rates of chromosome variation but also greatly lowered the seed viability and seedling survivability.ConclusionsIrradiation has been successfully employed to induce chromosome introgressions and chromosome translocations and promote chromosome exchanges between cultivated and wild species. In addition, by balancing the rates of chromosome introgression and translocation to those of seed set, seed germination, and seedling rates in the M1 generation, we conclude that the dosage of 20 Grays is the most suitable. The established methodology may guide the utilization of the tertiary gene pool of Gossypium species such as G. australe in cotton breeding in the future.Electronic supplementary materialThe online version of this article (10.1186/s12864-017-4398-7) contains supplementary material, which is available to authorized users.

Genome sequencing of the Australian wild diploid species Gossypium australe highlights disease resistance and delayed gland morphogenesis

“…Wilt disease caused by V. dahlia is the most devastating disease of cotton crops in several parts of the world, including China (Zhang et al ., ). Because the main cultivated upland cotton species ( G. hirsutum ) lacks genetic resources conferring resistance to Verticillium wilt, researchers have surveyed for such resistance genes from relatives such as, G. barbadense (Gao et al ., ; Miao et al ., ; Sun et al ., , ; Wang et al ., ; Xiang et al ., ; Zhang et al ., ; Zhou et al ., ) and other wild species, including G. australe (Benbouza et al ., ; Tang et al ., ; Wang et al ., ,).…”

“…To date, cotton genomics researchers have developed high‐quality reference sequences for 2 diploid groups, as well as allotetraploid cottons (‘A‐genome’, ‘D‐genome’ and ‘AD‐genome’ clade) including 3 cultivated species (AA, G. arboreum , AADD, G. hirsutum and G. barbadense ) and 1 wild ancestor species (DD, G. raimondii ) (Du et al ., ; Hu et al ., ; Li et al ., , ; Paterson et al ., ; Wang et al ., , ; Zhang et al ., ). Comparatively little research attention has been focused on Australian cotton species such as G. australe (with its ‘GG’ genome in cotton genomics nomenclature) (Chen et al ., ; Liu et al ., ; Wang et al ., ).…”

“…Gossypium australe has been an important resource in the era of modern cotton genomics. Specifically, G. australe is highly resistant to Verticillium wilt disease (Benkang and Cun, ; Gu et al ., ; Wang et al ., ) and is therefore viewed and has already been used as an important germplasm resource for the genetic improvement of cultivated upland cotton to increase resistance to Verticillium dahliae, seeking the inducement and identification of chromosome introgressions and translocations into G. hirsutum , as well as in the construction of a complete set of alien chromosome addition lines into G. hirsutum that were generated with aim of exploiting G. australe 's distinct traits including glanded‐plant and glandless‐seed and resistances to pests and diseases (Benbouza et al ., ; Chen et al ., ; Liu et al ., ; Wang et al ., ).…”

A High-Throughput Skim-sequencing Approach for Genotyping, Dosage Estimation and Identifying Translocations

“…Wide-crossing and introgression of novel haplotypes provides a way to access higher levels of genetic diversity that are not available in elite cultivars 32 , as many crops have gone through domestication and breeding bottlenecks 33 . For instance, successful alien introgression of various genes has been reported in rice 34 , in cotton (Gossypium hirsutum) 35 , and in maize 36 . In wheat, there are multiple instances of agronomically very important alien introgressions/translocations.…”

The complete chloroplast genome sequence of Neopallasia pectinata (Asteraceae)

“… 2017 ), and assembly script from Github (Wang et al. 2018 ). The final cp-genome of N. pectinata was annotated using the GeSeq annotation tool (Michael et al.…”