海水组培法培育芦荟耐盐品系研究

Studies of Culture and Propagation of Salt-tolerant Aloe Plantlet by Seawater Tissue Culture

以库拉索芦荟（Aloe vera）组培苗为材料,在培养基中添加不同浓度海水对芦荟进行盐胁迫驯化培养.结果显示：（1）在50%海水处理的组培植株性状分离最明显,且有部分芦荟苗生长旺盛;盐胁迫驯化前芦荟（库拉索）与盐胁迫驯化后芦荟（南盐1号）的组培苗在分化过程中存在明显的差异,库拉索芦荟的芽分化率、平均分芽数、心叶生长速率及生根系数等指标均明显低于同比例海水处理下的南盐1号;南盐1号芦荟苗在0-20%海水条件下组培时,芦荟分化率随着海水浓度的加大而降低,而30%海水组培处理时芦荟芽增长数上升至淡水组培水平,且平均心叶数增加速率最大,根生长变化特征与其芽分化生长基本一致.（2）移栽入圃后用50%天然海水灌溉时,南盐1号芦荟植株根系发达,生长正常,而库拉索芦荟则盐胁迫症状明显;经一年大田海水灌溉比较试验发现,南盐1号的地上部与根部的鲜重在淡水灌溉下与库拉索芦荟没有差异,而在30%和60%比例的海水灌溉下均显著高于库拉索芦荟;用30%的海水灌溉培养下,南盐1号地上部产量与淡水灌溉的产量无显著差异,而库拉索芦荟的地上部产量却比淡水处理降低15%-20%.研究表明,通过海水组织培养能筛选出芦荟耐盐株系,且其耐盐分化株系筛选的最适浓度为50%海水.

Moderate salt-tolerant Aloe vera plants in the field were used as explants to cultivate. During the culture, seawater concentration was gradually added to the medium with 0%→10%→20%→30%→40%→50%→60% for acclimation culture. The results showed that the growth and shape of the tissue-cultured plantlet by seawater stress was provided with obvious characters, especially at 50% seawater, parts of plants still flourished. There were many remarkable differences in differentiation between the domesticated salt-tolerant plantlet and control plantlet. Differentiation rate, the average shoot number, young leaf growth rate and radication coefficient of the domesticated salt-tolerant plantlet were higher than those of control. The differentiation rate of domesticated plantlet decreased along with seawater proportion from 0 to 20 %. There were not significant difference on the average shoot numbers between 30 % seawater tissue culture and non-seawater tissue culture. The average young leaf numbers were the highest both 30 % seawater tissue culture and non-seawater tissue culture among all treatments. The characteristics of radication growth of domesticated seedlings were accordant with their differentiation growth. The property of salt-tolerant differentiated plantlets （50% seawater） was stabilized after subculture again and again. Then they were transplanted with the same seawater irrigation. We found that the roots of these plants were able-bodied and showed normal growth. They showed more seawater tolerance from their appearances and shapes. The plantlet was provisionally named ‘Nanyan 1＇. There were no differences of the fresh weight of roots and shoots between ‘Nanyan 1＇ and Aloe vera （Control） with freshwater irrigation,while the fresh weight of roots and shoots of ‘Nanyan 1 ＇ significantly increased than those of Aloe vera with 30% and 60 % seawater irrigation. Compared with freshwater irrigation, there was no significant difference in fresh weight of shoots of ‘Nanyan 1’ with 30% seawater irrigation. However, compared with freshwater irrigation, fresh weight of shoots of Aloe vera （Control） with 30% seawater irrigation decreased by 15%-20%. Therefore,salt- tolerant Aloe vera plantlets can be isolated and screened by gradually adding the salinity to the medium for inducing salt responsion gene in plant strengthening expression.