保水技术对干旱胁迫下桔梗种子萌发及幼苗生长和生理特征的影响

以完整饱满的桔梗种子为材料,采用沙培控水方法进行盆栽实验,在沙粒(500g/盆)中分别均匀混入不同浓度梯度的保水剂(SAP)、保水剂与Na基膨润土(SAP+Na)、保水剂与Ca基膨润土(SAP+Ca)共3种保水处理技术,研究了不同保水技术对桔梗种子萌发以及幼苗生长、抗旱生理指标的影响。结果显示:1g SAP、(1+9)~(1.5+2)g SAP+Na、(1+9)g SAP+Ca均可显著提高桔梗种子的萌发,促进根系的生长速率,增加叶片中的相对含水量,增强叶片SOD、CAT活性,提高叶片游离脯氨酸、可溶性多糖及可溶性蛋白含量,减少干旱胁迫对细胞膜的破坏,有效降低了相对电导率,同时,处理提高了叶片中叶绿素与类胡萝卜素含量,增强了叶片产生光合色素的能力,有效增加ASA、GSH的含量,从而可抵御干旱造成的氧化胁迫,但随着混施浓度的增大,桔梗叶面抵御干旱胁迫的能力则会下降。研究表明,混施一定浓度SAP、SAP+Na和SAP+Ca可有效提供桔梗种子萌发所需适宜环境,减轻干旱胁迫对桔梗幼苗的伤害,且保水剂中混施Na基膨润土或者Ca基膨润土比单纯施保水剂效果更加明显。

Effect of Water Conservation Technique on Seeds Germination,Seedling Growrh and Physiological Characteristics of Platycodon grandiflorum

An experiment with complete the full Platycodon grandiflorum seeds as the material,water control in sand culture method is adopted to improve the potted experiment,in the grains of sand(500 g/pot) are mixed with gradient process of super absorbent polymers (SAP),super absorbent polymers and Na bentonite (SAP+Na),super absorbent polymers and Ca bentonite (SAP+Ca),a total of three kinds of water conservation technique.This paper studied the effects of 3 water conservation techniques and different concentrations on the germination of seed and the seedling drought resistance of P.grandiflorum by planting in sands.The results showed that the 1g SAP,(1+9)-(1.5+2) g SAP+Na and(1+9) g SAP+Ca was beneficial to seed germination rate,root growth rate and increased leaf relative water content of P.grandiflorum,enhanced the activities of SOD and CAT,the contents of proline,soluble polysaccharide and soluble protein,effectively reduced the damage of heat stress on cell membrane.At the same time,the contents of chlorophyll and carotenoid,the efficiency of leaf photosynthesis were increased,the ASA and GSH contents were also increased,and thus effectively resisted the oxidative stress caused by drought stress.However,with the increasing concentration of spraying,P.grandiflorum decreased the ability to resist drought stress.In conclusion,mix a certain concentration of SAP,SAP+Na and SAP+Ca can effectively provide good environment for seed germination,alleviate the harm for P.grandiflorum seedling by drought stress.Mixed super absorbent polymers and Na(Ca) bentonite is more efficient than simply mixed super absorbent polymers.