邻苯二甲酸对不同砧木西瓜嫁接苗根系生理特性及矿物质含量的影响

Effect of Phthalic Acid on Root Physiological Characteristics and Mineral Content of Grafted Watermelon Seedlings with Different Rootstocks

为研究不同砧木嫁接对西瓜化感物质的缓解作用,以西瓜品种‘早佳84-24’为接穗,用2种葫芦(‘京欣砧’和‘砧秋’)和2种南瓜(‘日本雪松’和‘酒砧一号’)为砧木,探究4 mmol·L^(-1)浓度邻苯二甲酸二异丁酯(DIBP)和邻苯二甲酸二辛酯(DOP)处理下,不同砧木嫁接对西瓜幼苗根系生理特性及矿质元素含量的影响。结果表明:(1)4 mmol·L^(-1)的DIBP和DOP处理下南瓜和葫芦嫁接苗的根长均长于自根苗,其中葫芦砧木具有更强的根系活力。(2)化感物质处理下4种嫁接苗的丙二醛(MDA)含量均显著降低,其中4 mmol·L^(-1)DIBP处理中4种嫁接苗均促进西瓜根系超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)活性的提高,而在4 mmol·L^(-1)DOP处理下,仅葫芦砧木促进了3种抗氧化酶活性提高。(3)化感物质处理下4种砧木嫁接苗硝酸还原酶活性整体上均高于自根苗。(4)化感物质处理下不同嫁接西瓜苗根系对矿质元素吸收呈现不同规律,总的来说嫁接可以促进根系对元素(磷、钾、钙、镁)的吸收,而抑制根系微量元素(铁、铜、锌)的积累。说明嫁接可以缓解脂肪酸酯对西瓜的化感作用,提高根系活力,减少对根系的生长抑制,促进抗氧化酶活性升高,减少MDA含量,影响根系对矿质元素的吸收,维持西瓜正常的生理活动。且葫芦嫁接苗对邻苯二甲酸的耐受性强于南瓜嫁接苗,其中‘京欣砧’作砧木效果最优。

To study the alleviated effect of grafting with different rootstocks on watermelon allelochemicals,watermelon variety‘Zaojia 84-24’was used as scion,two kinds of gourd(‘Jingxin Zhen’and‘Zhenqiu’)and two kinds of pumpkin(‘Ribenxuesong’and‘Jiuzhen No.1’)as rootstock,the effects of diisobutyl phthalate(DIBP)and dioctyl phthalate(DOP)at 4 mmol·L^(-1) concentration,and effects of grafting with different rootstocks on root physiological characteristics and mineral elements content of watermelon seedlings were investigated.The results showed that:(1)the root length of grafted seedlings of pumpkin and calabash was longer than that of self-rooted seedlings under 4 mmol·L^(-1) DIBP and DOP treatment,and calabash rootstock had stronger root activity.(2)The malondialdehyde content of the four grafted seedlings under allelochemicals treatment significantly decreased,and the activities of superoxide dismutase(SOD),peroxidase(POD)and peroxidase(CAT)of the four grafted seedlings under 4 mmol·L^(-1) DIBP treatment were improved.Only gourd rootstock promoted the activities of three antioxidant enzymes.(3)Nitrate reductase activity of grafted seedlings of four rootstocks treated with allelochemicals was higher than that of self-rooted watermelon.(4)Under allelochemicals treatment,the absorption of mineral elements in roots of different grafted watermelon seedlings showed different rules.In general,grafted watermelon seedlings could promote the absorption of elements(phosphorus,potassium,calcium,magnesium),but inhibit the accumulation of trace elements(iron,copper,zinc)in roots.It is suggested that grafting can alleviate allelopathic effect of fatty acid ester on watermelon,improve root activity,reduce root growth inhibition,promote antioxidant enzyme activity,reduce malondialdehyde content accumulation,affect root absorption and accumulation of mineral elements,and maintain normal physiological activities of watermelon.The tolerance of calabash grafted seedlings to allelochemicals was stronger than that of pumpkin grafted seedlings,and‘Jingxin stock’was the best rootstock.