1
|
Gowda SA, Bourland FM, Kaur B, Jones DC, Kuraparthy V. Genetic diversity and population structure analyses and genome-wide association studies of photoperiod sensitivity in cotton (Gossypium hirsutum L.). TAG. THEORETICAL AND APPLIED GENETICS. THEORETISCHE UND ANGEWANDTE GENETIK 2023; 136:230. [PMID: 37875695 DOI: 10.1007/s00122-023-04477-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/2023] [Accepted: 10/04/2023] [Indexed: 10/26/2023]
Abstract
KEY MESSAGE Genetic diversity and population structure analyses showed progressively narrowed diversity in US Upland cotton compared to land races. GWAS identified genomic regions and candidate genes for photoperiod sensitivity in cotton. Six hundred fifty-seven accessions that included elite cotton germplasm (DIV panel), lines of a public cotton breeding program (FB panel), and tropical landrace accessions (TLA panel) of Gossypium hirsutum L. were genotyped with cottonSNP63K array and phenotyped for photoperiod sensitivity under long day-length conditions. The genetic diversity analysis using 26,952 polymorphic SNPs indicated a progressively narrowed diversity from the landraces (0.230) to the DIV panel accessions (0.195) and FB panel (0.116). Structure analysis in the US germplasm identified seven subpopulations representing all four major regions of the US cotton belt. Three subpopulations were identified within the landrace accessions. The highest fixation index (FST) of 0.65 was found between landrace accessions of Guatemala and the Plains-type cultivars from Southwest cotton region while the lowest FST values were between the germplasms of Mid-South and Southeastern regions. Genome wide association studies (GWAS) of photoperiod response using 600 phenotyped accessions identified 14 marker trait associations spread across eight Upland cotton chromosomes. Six of these marker trait associations, on four chromosomes (A10, D04, D05, and D06), showed significant epistatic interactions. Targeted genomic analysis identified regions with 19 candidate genes including Transcription factor Vascular Plant One-Zinc Finger 1 (VOZ1) and Protein Photoperiod-Independent Early Flowering 1 (PIE1) genes. Genetic diversity and genome wide analyses of photoperiod sensitivity in diverse cotton germplasms will enable the use of genomic tools to systematically utilize the tropical germplasm and its beneficial alleles for broadening the genetic base in Upland cotton.
Collapse
Affiliation(s)
- S Anjan Gowda
- Crop and Soil Sciences Department, North Carolina State University, Raleigh, NC, 27695, USA
| | - Fred M Bourland
- NE Research and Extension Center, Crop, Soil, and Environmental Sciences, University of Arkansas, Keiser, AR, 72351, USA
| | - Baljinder Kaur
- Crop and Soil Sciences Department, North Carolina State University, Raleigh, NC, 27695, USA
| | - Don C Jones
- Cotton Incorporated, 6399 Weston Parkway, Cary, NC, 27513, USA
| | - Vasu Kuraparthy
- Crop and Soil Sciences Department, North Carolina State University, Raleigh, NC, 27695, USA.
| |
Collapse
|
2
|
Zhang L, Yu Y, Zhang M, Rong K, Wu Y, Zhang M, Hu H. Genome-wide identification of xylan glucuronosyltransferase family in cotton and function characterization of GhGUX5 in regulating Verticillium wilt resistance. Int J Biol Macromol 2023:124795. [PMID: 37207759 DOI: 10.1016/j.ijbiomac.2023.124795] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2022] [Revised: 03/26/2023] [Accepted: 04/27/2023] [Indexed: 05/21/2023]
Abstract
Xylan glucuronosyltransferase (GUX) is widely involved in a variety of physiological processes in plants, including plant development, growth and the defense response to pathogens. However, the function of GUX regulators in Verticillium dahliae (V. dahliae) infection has not been considered previously in cotton. Overall, 119 GUX genes were identified from multiple species and were phylogenetically categorized into seven classes. Duplication event analysis indicated that GUXs in Gossypium hirsutum primarily originated from segmental duplication. GhGUXs promoter analysis indicated cis-regulatory elements capable of reacting to several different stresses. RNA-Seq data and qRT-PCR analysis both indicated that most GhGUXs were associated with V. dahliae infection. Gene interaction network analysis showed that GhGUX5 interacted with 11 proteins, and the relative expression of these 11 proteins changed significantly following V. dahliae infection. In addition, silencing and overexpression of GhGUX5 results to enhance and reduce plant's susceptibility to V. dahliae. Further study showed that TRV: GhGUX5 silenced cotton plants exhibited a decrease in the degree of lignification, total lignin content, gene expression levels involved in lignin biosynthesis, and enzyme activity compared with TRV: 00. The above results indicate that GhGUX5 enhances Verticillium wilt resistance through the lignin biosynthesis pathway.
Collapse
Affiliation(s)
- Lei Zhang
- School of Life Science and Technology, Henan Institute of Science and Technology, Xinxiang 453003, China
| | - Yongang Yu
- School of Life Science and Technology, Henan Institute of Science and Technology, Xinxiang 453003, China
| | - Meng Zhang
- School of Life Science and Technology, Henan Institute of Science and Technology, Xinxiang 453003, China
| | - Kaikuo Rong
- School of Life Science and Technology, Henan Institute of Science and Technology, Xinxiang 453003, China
| | - Yanxia Wu
- School of Life Science and Technology, Henan Institute of Science and Technology, Xinxiang 453003, China
| | - Mingxia Zhang
- School of Life Science and Technology, Henan Institute of Science and Technology, Xinxiang 453003, China.
| | - Haiyan Hu
- School of Life Science and Technology, Henan Institute of Science and Technology, Xinxiang 453003, China.
| |
Collapse
|
3
|
Zhou J, Zhao L, Wu Y, Zhang X, Cheng S, Wei F, Zhang Y, Zhu H, Zhou Y, Feng Z, Feng H. A DEK domain-containing protein GhDEK2D mediated Gossypium hirsutum enhanced resistance to Verticillium dahliae. PLANT SIGNALING & BEHAVIOR 2022; 17:2024738. [PMID: 35034577 PMCID: PMC9176258 DOI: 10.1080/15592324.2021.2024738] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
DEK is associated with DNA replication and break repair, mRNA splicing, and transcriptional regulation, which had been studied in humans and mammals. The function of DEK in plants was poorly understood. In this study, GhDEK2D was identified in Gossypium hirsutum by genome-wide and post-translational modifications. GhDEK2D had been phosphorylated, acetylated and ubiquitylated under Verticillium dahliae (Vd) challenge. The GhDEK2D-silenced cotton decreased resistance against Vd. In GhDEK2D-silenced cotton plants, the reactive oxygen species was activated, the callose, xylogen, hypersensitive reaction (HR) and expression levels of defense-related genes were reduced. Homozygous overexpressing-GhDEK2D transgenic Arabidopsis lines were more resistant to Verticillium wilt (Vw). We propose that GhDEK2D was a potential molecular target for improving resistance to Vw in cotton.
Collapse
Affiliation(s)
- Jinglong Zhou
- College of Agriculture, Yangtze University, Jingzhou, China
- State Key Laboratory of Cotton Biology, Institute of Cotton Research of Chinese Academy of Agricultural Sciences, Anyang, China
- Yi Zhou College of Agriculture, Yangtze University, Jingzhou, Hubei 434025, China
| | - Lihong Zhao
- State Key Laboratory of Cotton Biology, Institute of Cotton Research of Chinese Academy of Agricultural Sciences, Anyang, China
- Yi Zhou College of Agriculture, Yangtze University, Jingzhou, Hubei 434025, China
| | - Yajie Wu
- State Key Laboratory of Cotton Biology, Institute of Cotton Research of Chinese Academy of Agricultural Sciences, Anyang, China
- Zhengzhou Research Base, State Key Laboratory of Cotton Biology, Zhengzhou University, Zhengzhou, China
| | - Xiaojian Zhang
- State Key Laboratory of Cotton Biology, Institute of Cotton Research of Chinese Academy of Agricultural Sciences, Anyang, China
- Zhengzhou Research Base, State Key Laboratory of Cotton Biology, Zhengzhou University, Zhengzhou, China
| | - Sheng Cheng
- College of Agriculture, Yangtze University, Jingzhou, China
| | - Feng Wei
- State Key Laboratory of Cotton Biology, Institute of Cotton Research of Chinese Academy of Agricultural Sciences, Anyang, China
- Zhengzhou Research Base, State Key Laboratory of Cotton Biology, Zhengzhou University, Zhengzhou, China
| | - Yalin Zhang
- State Key Laboratory of Cotton Biology, Institute of Cotton Research of Chinese Academy of Agricultural Sciences, Anyang, China
| | - Heqin Zhu
- State Key Laboratory of Cotton Biology, Institute of Cotton Research of Chinese Academy of Agricultural Sciences, Anyang, China
- Zhengzhou Research Base, State Key Laboratory of Cotton Biology, Zhengzhou University, Zhengzhou, China
| | - Yi Zhou
- College of Agriculture, Yangtze University, Jingzhou, China
- Yi Zhou College of Agriculture, Yangtze University, Jingzhou, Hubei 434025, China
| | - Zili Feng
- State Key Laboratory of Cotton Biology, Institute of Cotton Research of Chinese Academy of Agricultural Sciences, Anyang, China
- Zili Feng State Key Laboratory of Cotton Biology, Institute of Cotton Research of Chinese Academy of Agricultural Sciences, Anyang, Henan 455000, China
| | - Hongjie Feng
- State Key Laboratory of Cotton Biology, Institute of Cotton Research of Chinese Academy of Agricultural Sciences, Anyang, China
- Zhengzhou Research Base, State Key Laboratory of Cotton Biology, Zhengzhou University, Zhengzhou, China
- CONTACT Hongjie Feng
| |
Collapse
|
4
|
Zou J, Hu W, Loka DA, Snider JL, Zhu H, Li Y, He J, Wang Y, Zhou Z. Carbon assimilation and distribution in cotton photosynthetic organs is a limiting factor affecting boll weight formation under drought. FRONTIERS IN PLANT SCIENCE 2022; 13:1001940. [PMID: 36212360 PMCID: PMC9532866 DOI: 10.3389/fpls.2022.1001940] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/24/2022] [Accepted: 09/05/2022] [Indexed: 06/16/2023]
Abstract
Previous studies have documented cotton boll weight reductions under drought, but the relative importance of the subtending leaf, bracts and capsule wall in driving drought-induced reductions in boll mass has received limited attention. To investigate the role of carbon metabolism in driving organ-specific differences in contribution to boll weight formation, under drought conditions. Controlled experiments were carried out under soil relative water content (SRWC) (75 ± 5)% (well-watered conditions, control), (60 ± 5)% (moderate drought) and (45 ± 5)% (severe drought) in 2018 and 2019 with two cultivars Yuzaomian 9110 and Dexiamian 1. Under severe drought, the decreases of photosynthetic rate (Pn) and carbon isotope composition (δ13C) were observed in the subtending leaf, bract and capsule wall, suggesting that carbon assimilation of three organs was restricted and the limitation was most pronounced in the subtending leaf. Changes in the activities of sucrose phosphate synthase (SPS), sucrose synthase (SuSy), invertases as well as the reduction in expression of sucrose transporter (GhSUT1) led to variabilities in the sucrose content of three organs. Moreover, photosynthate distribution from subtending leaf to seeds plus fibers (the components of boll weight) was significantly restricted and the photosynthetic contribution rate of subtending leaf to boll weight was decreased, while contributions of bracts and capsule wall were increased by drought. This, in conjunction with the observed decreases in boll weight, indicated that the subtending leaf was the most sensitive photosynthetic organ to drought and was a dominant driver of boll weight loss under drought. Therefore, the subtending leaf governs boll weight loss under drought due to limitations in carbon assimilation, perturbations in sucrose metabolism and inhibition of sucrose transport.
Collapse
Affiliation(s)
- Jie Zou
- Key Laboratory of Crop Growth Regulation, Ministry of Agriculture, Nanjing Agricultural University, Nanjing, China
| | - Wei Hu
- Key Laboratory of Crop Growth Regulation, Ministry of Agriculture, Nanjing Agricultural University, Nanjing, China
| | - Dimitra A. Loka
- Institute of Industrial and Forage Crops, Hellenic Agricultural Organization, Larissa, Greece
| | - John L. Snider
- Department of Crop and Soil Sciences, University of Georgia, Tifton, GA, United States
| | - Honghai Zhu
- Key Laboratory of Crop Growth Regulation, Ministry of Agriculture, Nanjing Agricultural University, Nanjing, China
| | - Yuxia Li
- Key Laboratory of Crop Growth Regulation, Ministry of Agriculture, Nanjing Agricultural University, Nanjing, China
| | - Jiaqi He
- Key Laboratory of Crop Growth Regulation, Ministry of Agriculture, Nanjing Agricultural University, Nanjing, China
| | - Youhua Wang
- Key Laboratory of Crop Growth Regulation, Ministry of Agriculture, Nanjing Agricultural University, Nanjing, China
| | - Zhiguo Zhou
- Key Laboratory of Crop Growth Regulation, Ministry of Agriculture, Nanjing Agricultural University, Nanjing, China
| |
Collapse
|
5
|
Population Genetics and Development of a Core Collection from Elite Germplasms of Xanthoceras sorbifolium Based on Genome-Wide SNPs. FORESTS 2022. [DOI: 10.3390/f13020338] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Xanthoceras sorbifolium is one of the most important species of woody oil. In this study, whole genome re-sequencing of 119 X. sorbifolium germplasms was conducted and, after filtering, 105,685,557 high-quality SNPs were identified, which were used to perform population genetics and core collection development analyses. The results from the phylogenetic, population structure, and principal component analyses showed a high level of agreement, with 119 germplasms being classified into three main groups. The germplasms were not completely classified based on their geographical origins and flower colors; furthermore, the genetic backgrounds of these germplasms were complex and diverse. The average polymorphsim information content (PIC) values for the three inferred groups clustered by structure analysis and the six classified color groups were 0.2445 and 0.2628, respectively, indicating a low to medium informative degree of genetic diversity. Moreover, a core collection containing 29.4% (35) out of the 119 X. sorbifolium germplasms was established. Our results revealed the genetic diversity and structure of X. sorbifolium germplasms, and the development of a core collection will be useful for the efficient improvement of breeding programs and genome-wide association studies.
Collapse
|
6
|
Zhou J, Wu Y, Zhang X, Zhao L, Feng Z, Wei F, Zhang Y, Feng H, Zhou Y, Zhu H. MPK homolog GhNTF6 was involved in cotton against Verticillium wilt by interacted with VdEPG1. Int J Biol Macromol 2022; 195:456-465. [PMID: 34920061 DOI: 10.1016/j.ijbiomac.2021.12.037] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2021] [Revised: 11/10/2021] [Accepted: 12/05/2021] [Indexed: 11/18/2022]
Abstract
Mitogen-activated protein kinases (MPKs) are important in regulating plant development and stress response. Rapid activation of MPKs in plants usually depends on its phosphorylated. In view of this situation, a phosphorylated GhNTF6 belonged to MPKs family was screened in cotton roots under Verticillium dahliae challenge by phosphoproteomics analysis. Expression of GhNTF6 in cotton plants was did not induce by V. dahliae infection, while, silencing GhNTF6 results to enhance cotton plants susceptibility to V. dahliae, overexpression - GhNTF6 enhance Arabidopsis plants survivability to V. dahliae. Moreover, the mutation of GhNTF6 at site Thr195 and Thy197 with the phosphorylation decreased the plant resistance to V. dahliae. Therefore, GhNTF6 phosphorylation is important in plants against V. dahliae. Further analysis demonstrated that GhNTF6 interacted with a V. dahliae endopolygalacturonase (VdEPG1) on the cell nucleus. We propose that GhNTF6 is a potential molecular target for improving resistance to Verticillium wilt in cotton.
Collapse
Affiliation(s)
- Jinglong Zhou
- College of Agriculture, Yangtze University, Jingzhou, Hubei 434025, China; State Key Laboratory of Cotton Biology, Institute of Cotton Research of Chinese Academy of Agricultural Sciences, Anyang, Henan 455000, China
| | - Yajie Wu
- State Key Laboratory of Cotton Biology, Institute of Cotton Research of Chinese Academy of Agricultural Sciences, Anyang, Henan 455000, China; Zhengzhou Research Base, State Key Laboratory of Cotton Biology, Zhengzhou University, Zhengzhou, Henan 450001, China
| | - Xiaojian Zhang
- State Key Laboratory of Cotton Biology, Institute of Cotton Research of Chinese Academy of Agricultural Sciences, Anyang, Henan 455000, China; Zhengzhou Research Base, State Key Laboratory of Cotton Biology, Zhengzhou University, Zhengzhou, Henan 450001, China
| | - Lihong Zhao
- State Key Laboratory of Cotton Biology, Institute of Cotton Research of Chinese Academy of Agricultural Sciences, Anyang, Henan 455000, China
| | - Zili Feng
- State Key Laboratory of Cotton Biology, Institute of Cotton Research of Chinese Academy of Agricultural Sciences, Anyang, Henan 455000, China
| | - Feng Wei
- State Key Laboratory of Cotton Biology, Institute of Cotton Research of Chinese Academy of Agricultural Sciences, Anyang, Henan 455000, China; Zhengzhou Research Base, State Key Laboratory of Cotton Biology, Zhengzhou University, Zhengzhou, Henan 450001, China
| | - Yalin Zhang
- State Key Laboratory of Cotton Biology, Institute of Cotton Research of Chinese Academy of Agricultural Sciences, Anyang, Henan 455000, China
| | - Hongjie Feng
- State Key Laboratory of Cotton Biology, Institute of Cotton Research of Chinese Academy of Agricultural Sciences, Anyang, Henan 455000, China; Zhengzhou Research Base, State Key Laboratory of Cotton Biology, Zhengzhou University, Zhengzhou, Henan 450001, China.
| | - Yi Zhou
- College of Agriculture, Yangtze University, Jingzhou, Hubei 434025, China.
| | - Heqin Zhu
- State Key Laboratory of Cotton Biology, Institute of Cotton Research of Chinese Academy of Agricultural Sciences, Anyang, Henan 455000, China; Zhengzhou Research Base, State Key Laboratory of Cotton Biology, Zhengzhou University, Zhengzhou, Henan 450001, China.
| |
Collapse
|
7
|
Zhou J, Feng Z, Liu S, Wei F, Shi Y, Zhao L, Huang W, Zhou Y, Feng H, Zhu H. CGTase, a novel antimicrobial protein from Bacillus cereus YUPP-10, suppresses Verticillium dahliae and mediates plant defence responses. MOLECULAR PLANT PATHOLOGY 2021; 22:130-144. [PMID: 33230892 PMCID: PMC7749748 DOI: 10.1111/mpp.13014] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/18/2020] [Revised: 09/08/2020] [Accepted: 10/16/2020] [Indexed: 05/12/2023]
Abstract
Verticillium wilt is a plant vascular disease caused by the soilborne fungus Verticillium dahliae that severely limits cotton production. In a previous study, we screened Bacillus cereus YUPP-10, an efficient antagonistic bacterium, to uncover mechanisms for controlling verticillium wilt. Here, we report a novel antimicrobial cyclodextrin glycosyltransferase (CGTase) from YUPP-10. Compared to other CGTases, six different conserved domains were identified, and six mutants were constructed by gene splicing with overlap extension PCR. Functional analysis showed that domain D was important for hydrolysis activity and domains A1 and C were important for inducing disease resistance. Direct effects of recombinant CGTase on V. dahliae included reduced mycelial growth, spore germination, spore production, and microsclerotia germination. In addition, CGTase also elicited cotton's innate defence reactions. Transgenic Arabidopsis thaliana lines that overexpress CGTase showed higher resistance to verticillium wilt. Transgenic CGTase A. thaliana plants grew faster and resisted disease better. CGTase overexpression enabled a burst of reactive oxygen species production and activated pathogenesis-related gene expression, indicating that the transgenic cotton was better prepared to protect itself from infection. Our work revealed that CGTase could inhibit the growth of V. dahliae, activate innate immunity, and play a major role in the biocontrol of fungal pathogens.
Collapse
Affiliation(s)
- Jinglong Zhou
- State Key Laboratory of Cotton BiologyInstitute of Cotton Research of Chinese Academy of Agricultural SciencesAnyangChina
- Zhengzhou Research BaseState Key Laboratory of Cotton BiologyZhengzhou UniversityZhengzhouChina
- College of AgricultureYangtze UniversityJingzhouChina
| | - Zili Feng
- State Key Laboratory of Cotton BiologyInstitute of Cotton Research of Chinese Academy of Agricultural SciencesAnyangChina
| | - Shichao Liu
- State Key Laboratory of Cotton BiologyInstitute of Cotton Research of Chinese Academy of Agricultural SciencesAnyangChina
| | - Feng Wei
- State Key Laboratory of Cotton BiologyInstitute of Cotton Research of Chinese Academy of Agricultural SciencesAnyangChina
- Zhengzhou Research BaseState Key Laboratory of Cotton BiologyZhengzhou UniversityZhengzhouChina
| | - Yongqiang Shi
- State Key Laboratory of Cotton BiologyInstitute of Cotton Research of Chinese Academy of Agricultural SciencesAnyangChina
| | - Lihong Zhao
- State Key Laboratory of Cotton BiologyInstitute of Cotton Research of Chinese Academy of Agricultural SciencesAnyangChina
| | - Wanting Huang
- State Key Laboratory of Cotton BiologyInstitute of Cotton Research of Chinese Academy of Agricultural SciencesAnyangChina
- Zhengzhou Research BaseState Key Laboratory of Cotton BiologyZhengzhou UniversityZhengzhouChina
| | - Yi Zhou
- College of AgricultureYangtze UniversityJingzhouChina
| | - Hongjie Feng
- State Key Laboratory of Cotton BiologyInstitute of Cotton Research of Chinese Academy of Agricultural SciencesAnyangChina
- Zhengzhou Research BaseState Key Laboratory of Cotton BiologyZhengzhou UniversityZhengzhouChina
| | - Heqin Zhu
- State Key Laboratory of Cotton BiologyInstitute of Cotton Research of Chinese Academy of Agricultural SciencesAnyangChina
- Zhengzhou Research BaseState Key Laboratory of Cotton BiologyZhengzhou UniversityZhengzhouChina
| |
Collapse
|
8
|
Genetic Analysis of the Transition from Wild to Domesticated Cotton ( Gossypium hirsutum L.). G3-GENES GENOMES GENETICS 2020; 10:731-754. [PMID: 31843806 PMCID: PMC7003101 DOI: 10.1534/g3.119.400909] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The evolution and domestication of cotton is of great interest from both economic and evolutionary standpoints. Although many genetic and genomic resources have been generated for cotton, the genetic underpinnings of the transition from wild to domesticated cotton remain poorly known. Here we generated an intraspecific QTL mapping population specifically targeting domesticated cotton phenotypes. We used 466 F2 individuals derived from an intraspecific cross between the wild Gossypium hirsutum var. yucatanense (TX2094) and the elite cultivar G. hirsutum cv. Acala Maxxa, in two environments, to identify 120 QTL associated with phenotypic changes under domestication. While the number of QTL recovered in each subpopulation was similar, only 22 QTL were considered coincident (i.e., shared) between the two locations, eight of which shared peak markers. Although approximately half of QTL were located in the A-subgenome, many key fiber QTL were detected in the D-subgenome, which was derived from a species with unspinnable fiber. We found that many QTL are environment-specific, with few shared between the two environments, indicating that QTL associated with G. hirsutum domestication are genomically clustered but environmentally labile. Possible candidate genes were recovered and are discussed in the context of the phenotype. We conclude that the evolutionary forces that shape intraspecific divergence and domestication in cotton are complex, and that phenotypic transformations likely involved multiple interacting and environmentally responsive factors.
Collapse
|