海雀稗体细胞低温筛选获得耐寒突变体

旨在细胞水平上建立海雀稗(Paspalum vaginatum Sw.)低温胁迫定向筛选耐寒突变体技术,为开展海雀稗耐寒品种选育提供新途经。于2008年1月以海雀稗Adalay品种(P.vaginatum cv.Adalay)的幼穗诱导产生的颗粒状愈伤组织为材料,分别在6℃和0℃低温条件下进行培养和筛选。试验结果:在6℃和0℃下,培养30 d,愈伤组织的绿苗分化率均在80%以上,比对照处理(培养温度26℃)绿苗分化率略有下降;培养45 d,绿苗分化率分别为60%和50%;培养60 d,绿苗分化率分别降至33%和23%。在0℃下培养75 d,愈伤组织完全丧失分化植株的能力;0℃培养0、30、45和60 d的再生植株叶片的半致死温度分别为:-5.69℃、-6.07℃、-6.35℃和-6.63℃。SRAP分子标记测定结果显示,特异性SRAP标记与海雀稗体细胞突变体的耐寒性相关。海雀稗颗粒状愈伤组织在0℃下培养和筛选45 d和60 d获得了耐寒突变体植株。

Acquirement of Chilling Tolerant Mutant by Somatic Screening of Low Temperature in Sea Dallisgrass (Paspalum vaginatum Sw.)

Sea dallisgrass (Paspalum vaginatum Sw.) has been used in warm climatic environment worldwide. The green period of P. vaginatum cv. Adalay is 7-25 d shorter than that of local varieties of Cynodon dactylon (L.) Pars. or Zoysia japonica Steud in Jiangsu and Zhejiang province. The somatic mutant screening technique under low temperature was established in this paper. The pellet calli were induced from immature infloresce of Adalay and then cultured at low temperature of 6℃ and 0℃, respectively. The results show that the shoot regeneration rate was above 80% after cultured 30 d at 6℃ or 0℃ which was a little bit lower than control treatment with culture temperature at 26℃. The shoot regeneration rate was 60% or 50% after cultured 45 d and 33% or 23% after cultured 60 d at 6℃ or 0℃, respectively. After cultured 75 d at 0℃, all the calli lost the capability of plant regeneration. The leaf LT_(50) of the regenerated plants cultured for 0, 30, 45, or 60 d at 0℃ was -5.69, -6.07,-6.35 and-6.63℃, respectively. The results of SRAP markers indicate that the specific SRAP markers were associated with the cold tolerance of somatic mutants. The chilling tolerant somatic mutants were acquired from Adalay pellet calli after cultured 45 and 60 d at 0℃ .