Location: Cotton Ginning ResearchTitle: Genetic variation in salt tolerance during seed germination in a backcross inbred line population and advanced breeding lines derived from upland cotton x pima cotton Author
Submitted to: Crop Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/15/2013
Publication Date: 8/8/2013
Citation: Tiwari, R.S., Picchioni, G., Steiner, R.L., Hughs, S.E., Jones, D.C., Zhang, J. 2013. Genetic variation in salt tolerance during seed germination in a backcross inbred line population and advanced breeding lines derived from upland cotton x pima cotton. Crop Science. 53(5):1974-1982. Interpretive Summary: Seed germination is a crucial phase of the cotton plant life cycle that affects its stand establishment and growing season productivity. Information on the effect of soils with high salt content on cottonseed germination is limited. Pima cotton (Gossypium barbadense) may be more salt tolerant during germination than Upland cotton (G. hirsutum) based on its evolutionary and breeding history. The objective of this study was to evaluate the salt tolerance at seedling germination of introgressed lines developed from hybrids of Upland and Pima varieties. There were two separate tests conducted on two different populations of breeding lines derived from different Upland and Pima parents (146 lines for Test 1 and 120 lines for Test 2). The test germination salt condition was 200 mM NaCl versus non-salt (control) conditions. Based on the reduction in seed germination under saline conditions, the Pima parents were significantly more salt tolerant than were the Upland parents. There were also significant differences in the two populations in their response to saline conditions in both tests. This study has provided some of the first evidence that the introduction of salt tolerance at seed germination from Pima into Upland may be possible.
Technical Abstract: Seed germination is a crucial phase of the plant life cycle that affects its establishment and productivity. However, information on salt tolerance at this phase is limited. Pima cotton (Gossypium barbadense L.) may be more salt tolerant during germination than Upland cotton (G. hirsutum L.) based on its evolutionary and breeding history. The objective of this study was to evaluate germination salt tolerance of introgressed lines derived from hybrids between the two species under standard control conditions. A backcross inbred line (BIL) population of 146 lines from a cross between Upland cotton cv. Sure-Grow 747 and Pima S-7 (Test 1), and 120 advanced breeding lines from Acala 1517-99 x Pima Phy 76 (Test 2) were evaluated for germination under 200 mM NaCl and non-salt (control) conditions. Based on reduction in seed germination under NaCl conditions, G. barbadense parents were significantly more tolerant than the Upland parents. There were significant effects of genotype, treatment, and genotype x treatment interaction in both tests. The heritability for seed germination was moderate, ranging from 0.39 to 0.43 with at least two genes estimated. The genetic result is corroborated by the identification of many salt tolerant BILs and advanced breeding lines. This study has provided one of the first lines of evidence that the introduction of salt tolerance at seed germination from Pima into Upland cotton may be attainable.