8种大花蕙兰抗寒性指标的筛选及评价

Cold resistance indexes identification and comprehensive evaluation of 8 Cymbidium hybridium

以组培出瓶10个月的8个品种大花蕙兰植株为试材,观测在10℃/0℃(日温/夜温)低温胁迫、25℃/15℃(日温/夜温)适温恢复条件下寒害指数、初始荧光值(F_0)、PSⅡ系统最大光化学量子产量(F_v/F_m)、相对电导率、丙二醛(MDA)含量、可溶性糖含量和可溶性蛋白含量的变化,并对其抗寒性进行评价.结果表明:(1)随着低温胁迫时间的延长,不同品种大花蕙兰的F_0、F_v/F_m、MDA含量、相对电导率和可溶性蛋白含量显著上升,可溶性糖含量先上升后下降,且随着抗寒性品种的不同其变化幅度和速度有所不同;(2)F_v/F_m与F0、MDA含量、相对电导率、可溶性蛋白含量均呈极显著相关,与可溶性糖含量显著相关,尤其与寒害指数的相关系数达94.4%,可作为抗寒性筛选的可靠指标之一;(3)8个品种大花蕙兰抗寒性强弱为:‘金玉满堂’>‘天之骄子’>‘马可’>‘黄金岁月’>‘红梅’>‘红霞’>‘翠玉’>‘福娘’.

To screen Cymbidium hybridium cultivar which a d a p t s to c o l d c l imate in n o r t h e r n China,8 varieties of 10-month C.hy- bridium were subject to cold stress for 1,3 and 5 d,with daytime temperature being 10℃ and night temperature being 0℃ writ-ten as 10/0℃ ）. After returning to growth cabinet temperature （25/15℃）for the s a m e durat i o n of c o l d t r e a t m e n t,r e spectively, cold injury index,minimal fluorescence （ f0 ）,maximal photochemistry efficiency （ fv/fm ）,electric conductivity （ EC） , m a l o n a l - dehyde （MDA）,soluble sugar content and soluble protein content were monitored,and followed by correlation analysis for compre-hensive evaluation. Results showed that F0,f v/f rn,MDA,EC and soluble protein c o n t e n t all i n c r e a s e d a s l o w - t e m p e r a t u r e treat-ment prolonged. While soluble sugar level firstly rose and then dropped. Magnitudes and rates of change varied among varieties. Fur- themiore,fv/frn was significantly correlated with f0, EC,MDA and soluble protein c o n t e n t,and m o d e r a t e l y correlated w i t h soluble sugar. Con’elation coefficient between fv/fm and chilling injury index was -0.944,indicating that fv/fm could be used as a reliable indicator of cold resistance of C.hybridium. H a rdiness of 8 types of C.hybridium f r o m h i g h to l o w w e r e C. ＇ G o l d e n Y e l l o w’, C . ＇ Lihi Tabidachi’,C.＇ Buddy Mark’,C. Lovely moon ＇ Croscent ’,C. ＇ Honey H e a r t ’,C. R o y a l R e d P r i n c e s s ＇ N o b u k o ’,C. Plair ＇Days Memory’,C. ＇ Fuku Musume’ .Key words： Cymbidium hybridium; co l d r e s i s t a n c e; identification; c o m p r e h e n s i v e evaluation