成熟时间和干贮藏对两种木蓼种子萌发的影响

Effects of seed maturation time and dry storage on germination of two Atraphaxis species

刺木蓼(Atraphaxis spinosa)和长枝木蓼(A.virgata)为蓼科木蓼属灌木,刺木蓼1a结果2次,分别于6月份和9月份成熟,而长枝木蓼果期较长,于10—11月份成熟。对2种木蓼不同成熟时间及干贮藏后的种子,进行萌发实验,结果表明:不同成熟时间的刺木蓼种子在30℃/20℃的萌发率高,长枝木蓼10月份成熟的种子在15℃/6℃的萌发率低,而11月份成熟的种子在15℃/6℃的萌发率最高。成熟早的刺木蓼种子较小,而长枝木蓼成熟晚的种子较小,不同成熟时间的2种木蓼种子均表现为,小种子的休眠程度低。刺木蓼不同成熟时间的种子在干贮藏的过程中,种子的萌发率先降低后增加。干贮藏明显提高了长枝木蓼种子在15℃/6℃的萌发率,尤其是10月份成熟的种子,10月份和11月份成熟的种子分别贮藏9个月和6个月后解除休眠。

The effect of seed maturation time and dry seed storage on final germination percentage for the native shrubs Atraphaxis spinosa and A. virgata,which grown under desert environmental conditions in Urumqi,is great. A. spinosa fruits two times annually,in June and September. A. virgata has a long florescence last out two months. A. spinosa seeds were collected in June and September,while A. virgata seeds were in October and November. Seeds were germinated immediately and after 3,6,9,12 and 15 months of dry storage under room temperature. Fresh seeds with different maturate time were germinated at 15℃/6℃,20℃/10℃,25℃/15℃ and 30℃/20℃ （day 12h/night 12h）. The seeds were germinated at 15℃/6℃ and 30℃/20℃ under the situation of dry storage. The results showed that the fresh seeds of A. spinosa were maturated in June and September germinated significantly greater at 30℃/20℃. The seeds of A. virgata matured in October had lower germination percentage at 15℃/6℃,but they were higher in November. These two Atraphaxis species have similitude mechanisms of germination. Their seeds maturate in different time have different level of dormancy. The seeds of A. spinosa maturating in June had higher germination comparing to matured in September. On the other hand,the seeds of A. virgata maturating in November had higher germination than matured in October. The wight of A. spinosa seeds in June were lighter than in September,while A. virgata seeds in November were lighter. The results showed that small seeds had higher germination percentage,big seeds of the two Atraphaxis species had longer dormant time. Under the condation of dry storage,the seeds of A. spinosa increased rapidly about the level of dormancy with time in the first 9 months,decreased with time in the next term. But dry storage increased germination percentage of A. virgata significantly at 15℃/6℃,it increased significantly in October than in November. A. spinosa seeds matured in October after 9 months while seeds matured in November needs 6 months＇ time of dry storage. This indicates that dormancy breakage was greater in November than that of October. Under the condition of dry storage,the seeds of A. virgata need low temperature to achieve greater germination percentage.