干热河谷牛角瓜育苗技术及幼苗生长节律

Breeding Technology and Seedling Growth Rhythm of Calotropis gigantean L.in Dry-hot Valley

为规范牛角瓜播种繁殖技术并指导生产,从种子处理、播种深度、播种季节三方面,探讨了牛角瓜种子发芽情况及幼苗生长节律。种子发芽试验表明,水浸催芽能提高牛角瓜种子发芽率,最高发芽率为92.65%,播种深度为1 cm时,发芽率和发芽势最高,方差分析差异分别达极显著(P<0.01)和显著(P<0.05),干种则随深度增加发芽率、萌发率、保存率均增加,这与营养土水分梯度有关;秋播较春播发芽率高,且发芽进程受温度影响小,萌发速率系数和萌发指数显示春播萌发较快,萌发指数差异显著(P<0.05)。幼苗生长试验表明,牛角瓜幼苗生长可分为慢生长期(0～20 d)、快速生长期(20～40 d)和慢生长期(60～80 d);播种深度不仅影响发芽率,还影响幼苗生长;春播幼苗受温度影响生长较秋播迅速;叶片数量呈现"增加-减少-增加"趋势,通过叶片自身营养消耗和叶片光合输出影响苗木生长。可见,牛角瓜育苗以晚春或初夏浸泡后浅播为宜。

To regulate propagation technique and guide the production, the seed germination and seed- ling growth rhythm of Calotropis gigantean were studied from seed treatment, planted depth and planted season. The results showed that flooded germination can increase the germination rate of Calotropis gi- gantean, the maximum germination rate was 92.65%. The highest germination rate and germination vigor were found that the planted depth with 1 cm, which were extremely significant （ P 〈 0. 01 ） and significant （ P 〈 0.05 ） with other treatments. The germination rate, germination percentage and sav- ing rate were increased with planting depth of dry seed. Thus, it is related to the distribution of water. The germination rate planted in autumn was higher than planted in spring, and little affected by tern-perature in germination processes. According to coefficient of rate of germination and germination in- dex, the seed planted in spring had the faster germination than planted in autmnn; also it has signifi- cant level in germination index （ P 〈 0. 05 ）. The seedling growth results showed that the seedling growth of C. gigantean can be divided into three periods： slow growth period （0 -20 d）, fast growth period （20 -40 d） and slow growth period （60 -80 d）. Planted depth not only affected the germina- tion rate, but also the seedling growth. Seedling growth in spring was more quickly than in autumn be- cause of temperature. During the seedling growth, the trend of leaves was ＂ increase-decrease-in- crease＂. Seedling growth was affected by leaf nutrient consumption and photosynthetic output. It can clearly be seen that C. gigantean to plant in late spring or early summer with soaking and shallow so- wing will be better.