Limits...
A new synthetic allotetraploid (A1A1G2G2) between Gossypium herbaceum and G. australe: bridging for simultaneously transferring favorable genes from these two diploid species into upland cotton.

Liu Q, Chen Y, Chen Y, Wang Y, Chen J, Zhang T, Zhou B - PLoS ONE (2015)

Bottom Line: Creating synthetic allotetraploid cotton from these two species would lay the foundation for simultaneously transferring favorable genes into cultivated tetraploid cotton.Here, we crossed G. herbaceum (as the maternal parent) with G. australe to produce an F1 interspecific hybrid and doubled its chromosome complement with colchicine, successfully generating a synthetic tetraploid.The synthetic allotetraploid will be quite useful for polyploidy evolutionary studies and as a bridge for transferring favorable genes from these two diploid species into Upland cotton through hybridization.

View Article: PubMed Central - PubMed

Affiliation: State Key Laboratory of Crop Genetics & Germplasm Enhancement, MOE Hybrid Cotton R&D Engineering Research Center, Nanjing Agricultural University, Nanjing, Jiangsu, People's Republic of China.

ABSTRACT
Gossypium herbaceum, a cultivated diploid cotton species (2n = 2x = 26, A1A1), has favorable traits such as excellent drought tolerance and resistance to sucking insects and leaf curl virus. G. australe, a wild diploid cotton species (2n = 2x = 26, G2G2), possesses numerous economically valuable characteristics such as delayed pigment gland morphogenesis (which is conducive to the production of seeds with very low levels of gossypol as a potential food source for humans and animals) and resistance to insects, wilt diseases and abiotic stress. Creating synthetic allotetraploid cotton from these two species would lay the foundation for simultaneously transferring favorable genes into cultivated tetraploid cotton. Here, we crossed G. herbaceum (as the maternal parent) with G. australe to produce an F1 interspecific hybrid and doubled its chromosome complement with colchicine, successfully generating a synthetic tetraploid. The obtained tetraploid was confirmed by morphology, cytology and molecular markers and then self-pollinated. The S1 seedlings derived from this tetraploid gradually became flavescent after emergence of the fifth true leaf, but they were rescued by grafting and produced S2 seeds. The rescued S1 plants were partially fertile due to the existence of univalents at Metaphase I of meiosis, leading to the formation of unbalanced, nonviable gametes lacking complete sets of chromosomes. The S2 plants grew well and no flavescence was observed, implying that interspecific incompatibility, to some extent, had been alleviated in the S2 generation. The synthetic allotetraploid will be quite useful for polyploidy evolutionary studies and as a bridge for transferring favorable genes from these two diploid species into Upland cotton through hybridization.

Show MeSH

Related in: MedlinePlus

Seed kernels of G. herbaceum (1), G. australe (2) and the new synthetic allotetraploid S1 (3).Numerous pigment glands on the cotyledon surface of G. herbaceum (1); no pigment glands on the cotyledon surface of G. australe (2); a few pigment glands on the cotyledon surface margin of the synthetic allotetraploid S1 (3).
© Copyright Policy
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4400159&req=5

pone.0123209.g005: Seed kernels of G. herbaceum (1), G. australe (2) and the new synthetic allotetraploid S1 (3).Numerous pigment glands on the cotyledon surface of G. herbaceum (1); no pigment glands on the cotyledon surface of G. australe (2); a few pigment glands on the cotyledon surface margin of the synthetic allotetraploid S1 (3).

Mentions: We examined 24 morphological traits of the synthetic allotetraploid (S1) and its parents during flowering, including the color, shape and size of leaves, flowers and so on (Table 2). The results indicate that most traits of the interspecific hybrid F1 plant tended to resemble those of the paternal parent, G. australe, e.g., hairiness of leaves and stems, petal color and fibers. A few traits resembled those of the maternal parent, G. herbaceum, e.g., anther color. Some traits exhibited intermediate phenotypes, e.g., bract shape, calyx size and the number of calyx teeth, leaf lobes, anthers, seed pigment glands and fiber (Figs 4 and 5, S2 Fig). Many characters of S1 plants, the new synthetic allotetraploid, were similar to those of the F1, while S1 plants had larger dark green leaves, which was the most distinctive trait from that of the F1 (Fig 6).


A new synthetic allotetraploid (A1A1G2G2) between Gossypium herbaceum and G. australe: bridging for simultaneously transferring favorable genes from these two diploid species into upland cotton.

Liu Q, Chen Y, Chen Y, Wang Y, Chen J, Zhang T, Zhou B - PLoS ONE (2015)

Seed kernels of G. herbaceum (1), G. australe (2) and the new synthetic allotetraploid S1 (3).Numerous pigment glands on the cotyledon surface of G. herbaceum (1); no pigment glands on the cotyledon surface of G. australe (2); a few pigment glands on the cotyledon surface margin of the synthetic allotetraploid S1 (3).
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4400159&req=5

pone.0123209.g005: Seed kernels of G. herbaceum (1), G. australe (2) and the new synthetic allotetraploid S1 (3).Numerous pigment glands on the cotyledon surface of G. herbaceum (1); no pigment glands on the cotyledon surface of G. australe (2); a few pigment glands on the cotyledon surface margin of the synthetic allotetraploid S1 (3).
Mentions: We examined 24 morphological traits of the synthetic allotetraploid (S1) and its parents during flowering, including the color, shape and size of leaves, flowers and so on (Table 2). The results indicate that most traits of the interspecific hybrid F1 plant tended to resemble those of the paternal parent, G. australe, e.g., hairiness of leaves and stems, petal color and fibers. A few traits resembled those of the maternal parent, G. herbaceum, e.g., anther color. Some traits exhibited intermediate phenotypes, e.g., bract shape, calyx size and the number of calyx teeth, leaf lobes, anthers, seed pigment glands and fiber (Figs 4 and 5, S2 Fig). Many characters of S1 plants, the new synthetic allotetraploid, were similar to those of the F1, while S1 plants had larger dark green leaves, which was the most distinctive trait from that of the F1 (Fig 6).

Bottom Line: Creating synthetic allotetraploid cotton from these two species would lay the foundation for simultaneously transferring favorable genes into cultivated tetraploid cotton.Here, we crossed G. herbaceum (as the maternal parent) with G. australe to produce an F1 interspecific hybrid and doubled its chromosome complement with colchicine, successfully generating a synthetic tetraploid.The synthetic allotetraploid will be quite useful for polyploidy evolutionary studies and as a bridge for transferring favorable genes from these two diploid species into Upland cotton through hybridization.

View Article: PubMed Central - PubMed

Affiliation: State Key Laboratory of Crop Genetics & Germplasm Enhancement, MOE Hybrid Cotton R&D Engineering Research Center, Nanjing Agricultural University, Nanjing, Jiangsu, People's Republic of China.

ABSTRACT
Gossypium herbaceum, a cultivated diploid cotton species (2n = 2x = 26, A1A1), has favorable traits such as excellent drought tolerance and resistance to sucking insects and leaf curl virus. G. australe, a wild diploid cotton species (2n = 2x = 26, G2G2), possesses numerous economically valuable characteristics such as delayed pigment gland morphogenesis (which is conducive to the production of seeds with very low levels of gossypol as a potential food source for humans and animals) and resistance to insects, wilt diseases and abiotic stress. Creating synthetic allotetraploid cotton from these two species would lay the foundation for simultaneously transferring favorable genes into cultivated tetraploid cotton. Here, we crossed G. herbaceum (as the maternal parent) with G. australe to produce an F1 interspecific hybrid and doubled its chromosome complement with colchicine, successfully generating a synthetic tetraploid. The obtained tetraploid was confirmed by morphology, cytology and molecular markers and then self-pollinated. The S1 seedlings derived from this tetraploid gradually became flavescent after emergence of the fifth true leaf, but they were rescued by grafting and produced S2 seeds. The rescued S1 plants were partially fertile due to the existence of univalents at Metaphase I of meiosis, leading to the formation of unbalanced, nonviable gametes lacking complete sets of chromosomes. The S2 plants grew well and no flavescence was observed, implying that interspecific incompatibility, to some extent, had been alleviated in the S2 generation. The synthetic allotetraploid will be quite useful for polyploidy evolutionary studies and as a bridge for transferring favorable genes from these two diploid species into Upland cotton through hybridization.

Show MeSH
Related in: MedlinePlus