新疆棉花4个主栽品种的体细胞胚胎发生及植株再生

以新疆4个主栽棉花品种新陆中20、新陆早24、新陆早33和03298为材料, 通过不同浓度的激素组合成功地诱导获得了体细胞胚并进一步发育成苗。研究发现, 所用的4种激素组合均能有效诱导愈伤组织, 其中又以0.02 mg L^-1或0.10 mg L^-1 KT和0.1 mg L^-1 2,4-D组合的诱导效果最佳; 两个诱导措施有利于胚性愈伤组织的产生, 即沿中柱纵切棉花下胚轴切段, 并以纵切面接触培养基; 愈伤组织诱导培养基中KNO₃用量加倍。挑选黄绿色、灰绿色或浅绿色的质地疏松的愈伤组织继代于无激素且KNO₃含量加倍的培养基中可产生胚性愈伤组织, 并在高比例KT/2, 4-D(0.05 mg L^-1或0.10 mg L^-1 KT和0.01 mg L^-1 2,4-D)促进下发育成胚。借助在培养基上垫滤纸产生干燥作用, 并间隔使用强透气效果的棉塞对培养三角瓶进行透气处理, 体细胞胚可成熟发育并产生根系发达的正常再生植株。应用此法, 4个实验材料在6~8个月内即可获得大量再生苗。

In vitro Regeneration of Four Commercial Cotton (Gossypium hirsutum L.) Cultivars Grown in Xinjiang, China

Cotton grown in Xinjiang is critical to successful cotton production in China. Genetic improvement in cotton via biotechnology is limited due to lack of an efficient regeneration system. Here, an efficient somatic embryo procedure was developed to regenerate plantlets from hypocotyls of cotton cultivars Xinluzhong 20, Xinluzao 24, Xinluzao 33 and 03298 grown in Xinjiang. Calli were effectively produced on the medium with 0.01–0.10 mg L^-1 Kinetin (KT) and 0.10 mg L^-1 2,4-Dichlorophenoxyacetic acid (2,4-D), especially with 0.02 or 0.10 mg L^-1 KT and 0.10 mg L^-1 2,4-D. Split hypocotyl segments and double amounts of KNO₃ in the medium during induction of calli were beneficial to the emerge of embryogenic calli. Embryogenic calli and globular-stage somatic embryos were effectively initiated with high concentration of KT and low concentration of 2,4-D in ECM media (0.05 or 0.10 mg L^-1 KT and 0.01 mg L^-1 2,4-D). Embryos further developed into plantlets in MSBF medium under conditions of dehydration and ventilization achieved respectively by filter paper on medium and cotton tampon sealing flask. Using this proto-col, normal plantlets with strong roots well developed from these cotton cultivars for 6 to 8 months, increasing the range of cotton genotypes that can be regenerated. The successful regeneration protocol established in this study can be used to improve cotton cultivars by genetic engineering.