Rong Yuan1, Yuefen Cao1, Tengyu Li1, Feng Yang1, Li Yu1, Yuan Qin2, Xiongming Du2, Fang Liu2, Mingquan Ding1, Yurong Jiang1, Hua Zhang1, Andrew H Paterson3, Junkang Rong4. 1. The Key Laboratory for Quality Improvement of Agricultural Products of Zhejiang Province, College of Agriculture and Food Science, Zhejiang A&F University, Lin'an, Zhejiang, 311300, Hangzhou, China. 2. Institute of Cotton Research, Chinese Academy of Agricultural Science (ICR, CAAS)/State Key Laboratory of Cotton Biology, Anyang, 455000, China. 3. Plant Genome Mapping Laboratory, University of Georgia, Athens, GA, 30605, USA. 4. The Key Laboratory for Quality Improvement of Agricultural Products of Zhejiang Province, College of Agriculture and Food Science, Zhejiang A&F University, Lin'an, Zhejiang, 311300, Hangzhou, China. jkrong@yahoo.com.
Abstract
BACKGROUND: Cotton stem trichomes and seed fibers are each single celled structures formed by protrusions of epidermal cells, and were found sharing the overlapping molecular mechanism. Compared with fibers, cotton stem trichomes are more easily observed, but the molecular mechanisms underlying their development are still poorly understood. RESULTS: In this study, Gossypium hirsutum (Gh) and G. barbadense (Gb) were found to differ greatly in percentages of varieties/accessions with glabrous stems and in trichome density, length, and number per trichopore. Gh varieties normally had long singular and clustered trichomes, while Gb varieties had short clustered trichomes. Genetic mapping using five F2 populations from crosses between glabrous varieties and those with different types of stem trichomes revealed that much variation among stem trichome phenotypes could be accounted for by different combinations of genes/alleles on Chr. 06 and Chr. 24. The twenty- six F1 generations from crosses between varieties with different types of trichomes had varied phenotypes, further suggesting that the trichomes of tetraploid cotton were controlled by different genes/alleles. Compared to modern varieties, a greater proportion of Gh wild accessions were glabrous or had shorter and denser trichomes; whereas a smaller proportion of Gb primitive accessions had glabrous stems. A close correlation between fuzz fiber number and stem trichome density was observed in both Gh and Gb primitive accessions and modern varieties. CONCLUSION: Based on these findings, we hypothesize that stem trichomes evolved in parallel with seed fibers during the domestication of cultivated tetraploid cotton. In addition, the current results illustrated that stem trichome can be used as a morphological index of fiber quality in cotton conventional breeding.
BACKGROUND: Cotton stem trichomes and seed fibers are each single celled structures formed by protrusions of epidermal cells, and were found sharing the overlapping molecular mechanism. Compared with fibers, cotton stem trichomes are more easily observed, but the molecular mechanisms underlying their development are still poorly understood. RESULTS: In this study, Gossypium hirsutum (Gh) and G. barbadense (Gb) were found to differ greatly in percentages of varieties/accessions with glabrous stems and in trichome density, length, and number per trichopore. Gh varieties normally had long singular and clustered trichomes, while Gb varieties had short clustered trichomes. Genetic mapping using five F2 populations from crosses between glabrous varieties and those with different types of stem trichomes revealed that much variation among stem trichome phenotypes could be accounted for by different combinations of genes/alleles on Chr. 06 and Chr. 24. The twenty- six F1 generations from crosses between varieties with different types of trichomes had varied phenotypes, further suggesting that the trichomes of tetraploid cotton were controlled by different genes/alleles. Compared to modern varieties, a greater proportion of Gh wild accessions were glabrous or had shorter and denser trichomes; whereas a smaller proportion of Gb primitive accessions had glabrous stems. A close correlation between fuzz fiber number and stem trichome density was observed in both Gh and Gb primitive accessions and modern varieties. CONCLUSION: Based on these findings, we hypothesize that stem trichomes evolved in parallel with seed fibers during the domestication of cultivated tetraploid cotton. In addition, the current results illustrated that stem trichome can be used as a morphological index of fiber quality in cotton conventional breeding.
Authors: Andrew H Paterson; Jonathan F Wendel; Heidrun Gundlach; Hui Guo; Jerry Jenkins; Dianchuan Jin; Danny Llewellyn; Kurtis C Showmaker; Shengqiang Shu; Joshua Udall; Mi-jeong Yoo; Robert Byers; Wei Chen; Adi Doron-Faigenboim; Mary V Duke; Lei Gong; Jane Grimwood; Corrinne Grover; Kara Grupp; Guanjing Hu; Tae-ho Lee; Jingping Li; Lifeng Lin; Tao Liu; Barry S Marler; Justin T Page; Alison W Roberts; Elisson Romanel; William S Sanders; Emmanuel Szadkowski; Xu Tan; Haibao Tang; Chunming Xu; Jinpeng Wang; Zining Wang; Dong Zhang; Lan Zhang; Hamid Ashrafi; Frank Bedon; John E Bowers; Curt L Brubaker; Peng W Chee; Sayan Das; Alan R Gingle; Candace H Haigler; David Harker; Lucia V Hoffmann; Ran Hovav; Donald C Jones; Cornelia Lemke; Shahid Mansoor; Mehboob ur Rahman; Lisa N Rainville; Aditi Rambani; Umesh K Reddy; Jun-kang Rong; Yehoshua Saranga; Brian E Scheffler; Jodi A Scheffler; David M Stelly; Barbara A Triplett; Allen Van Deynze; Maite F S Vaslin; Vijay N Waghmare; Sally A Walford; Robert J Wright; Essam A Zaki; Tianzhen Zhang; Elizabeth S Dennis; Klaus F X Mayer; Daniel G Peterson; Daniel S Rokhsar; Xiyin Wang; Jeremy Schmutz Journal: Nature Date: 2012-12-20 Impact factor: 49.962