The pellet embryonic calli of Paspalum vagiantum Sw.cv.Adalay were used for 60Co γ-rays irradiation.In the callus subculture medium with 2,4-D 2.0mg/L and BAP 0.05mg/L,calli were irradiated at the dose rate 1 Gy/min of 60Co γ-rays.Results showed that the rate of shoot regeneration was from 94% to 85% when calli irradiated with 20～50 Gy;the rate of shoot regeneration was from 76% to 30% ,and the rate of plant regeneration was from 44.5% to 8.7% between 60～80 Gy.By 60 Gy of 60Co γ-rays irradiation,the rate of shoot regeneration was about 76% in the differentiation medium with BAP 2.0mg/L,and the relative rate of plant regeneration was 44.5% in the rooting medium with NAA 0.5mg/L.The result of sequence-related amplified polymorphism(SRAP) markers analysis showed that the specific SRAP markers were associated with the somatic mutants.The mutation technique of 60 Co γ-rays has been established in the somatic cell of Paspalum vaginatum Sw.

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.

以海雀稗品种Adalay（Paspalum vaginatum Sw.cv.Adalay）的颗粒状胚性愈伤组织为材料,在离体培养条件下研究不同剂量的60Coγ射线辐照对愈伤组织绿苗分化和植株再生的影响。结果显示,辐照剂量在20～50Gy时,辐照处理的愈伤组织分化绿苗的频率从94%左右降至85%;剂量在60～80Gy时,愈伤组织的绿苗分化率从76%左右降至30%左右,相对植株再生率从44.5%降至8.7%。60Gy为辐照处理海雀稗颗粒状愈伤组织的适宜剂量,辐照处理的愈伤组织在附加BAP2.0mg/L的愈伤组织分化培养基上,绿苗分化率在76%左右,分化的绿苗转到附加NAA0.5mg/L的生根培养基上,相对植株再生率为44.5%。SRAP分子标记测定结果显示,特异性SRAP标记与体细胞辐照诱变突变体相关。本研究建立起海雀稗体细胞60Coγ射线辐照诱变技术,为在细胞水平上开展海雀稗辐照诱变育种提供条件。

Sea dallisgrass(Paspalum vaginatum Sw.) is a prospective candidate for use on golf courses,athletic fields,and landscape areas in warm climatic environment worldwide.Plant regeneration is the basic technique for the genetic improvement through biotechnology.This paper described an establishment procedure of the plant regeneration system in vitro.The immature infloresces of P.vaginatum Sw.cv.Adalay were used for the explant materials.In the modified MS medium supplemented with 2.0~4.0 mg·L-12,4-D,the rate of callus induction was up to 90%.The different development stages of immature infloresces affected on the frequency of callus induction.The rate of callus induction was above 80% for the inflorescence with 1.0-2.0 cm length and below 60% for over 2.0 cm.The rate of pellet callus was up to 40% in the callus induction medium plus 2.0 mg·L-12,4-D and 0.05 mg/L BAP.During callus subculture,callus maintained the pellet status in the same medium supplemented with 16 g·L-1 agar.After three subcutures of the pellet callus,the frequency of shoot regeneration was 98% in the differentiation medium with 2.0 mg·L-1 BAP.Pellet structure and high shoot regeneration frequency of P.vaginatum pellet callus were maintained by increasing the osmotic pressure of callus induction medium.

海雀稗(Paspalum vaginatum Sw)具有较高的耐盐、耐干旱、耐涝和耐磨损性,作为草坪草,在世界热带与亚热带地区广为种植,是继狗牙根、结缕草和假俭草等暖季型禾草之后兴起的后起之秀[1].海雀稗在中国主要分布于台湾、云南、广东和海南等省.