【作者】 刘成静；

【导师】 张志忠；

【作者基本信息】 福建农林大学 ， 蔬菜学， 2010， 硕士

【摘要】 本研究主要通过探讨温室内根结线虫对嫁接西瓜生长发育的影响,根结线虫侵染后西瓜的生理生化变化,进而阐明嫁接西瓜对根结线虫的抗性生理机制;探讨温度逆境对西瓜嫁接苗生长发育的影响,温度逆境下西瓜嫁接苗的生理生化变化及其机理。试验以金星和春秀为接穗,以博大嫁接王、青砧1号、黑籽南瓜、黑南瓜、瓠瓜、大葫芦12号、白籽丝瓜、全能铁甲、莱砧1号、圣砧1号为砧木,主要研究结果如下。1、西瓜嫁接砧木的筛选通过对砧木嫁接后嫁接苗成活率、生长势和果实性状指标的数据综合分析,从10个砧木材料中筛选出莱砧1号、黑籽南瓜、全能铁甲、大葫芦12号、圣砧1号5个综合表现较好的砧木。2、根结线虫对西瓜嫁接苗的影响西瓜嫁接苗接种根结线虫后,根系PAL、TAL、PPO、O2-.含量、SOD活性、CAT活性及总酚含量均是嫁接苗高于自根苗,不同砧木接穗组合略有差异;而POD活性自根苗高于嫁接苗,全能铁甲/春秀高于大葫芦12号/春秀。根结线虫侵入后根系MDA含量持续增加,但以自根苗为高;根结线虫侵染西瓜60 d后,嫁接苗根结指数低于自根苗,线虫危害较轻,而葫芦/春秀嫁接苗根结指数低于全能铁甲/春秀;根结线虫侵染会导致西瓜株高、叶片数、叶面积下降,单果重、总糖、VC、游离氨基酸含量下降,可溶性蛋白含量升高。3、西瓜根系分泌物对线虫卵孵化的影响不接种根结线虫时,西瓜自根苗及嫁接苗根系分泌物对线虫卵孵化的影响不是很大。从整个孵化过程来看,接种根结线虫后自根苗根系分泌物对根结线虫卵孵化具有显著的刺激作用,而嫁接苗的根系分泌物则对线虫卵孵化具有抑制作用。4、温度逆境对西瓜嫁接苗的影响在本试验中高温胁迫下,接穗相同而砧木不同的嫁接苗耐热能力,从大到小依次为圣砧1号/金星>莱砧1号/金星>黑籽南瓜/金星>大葫芦12号/金星>全能铁甲/金星>金星;圣砧1号/春秀>黑籽南瓜/春秀>大葫芦12号/春秀>莱砧1号/春秀>全能铁甲/春秀>春秀。低温胁迫下,接穗相同而砧木不同的嫁接苗耐寒能力从大到小依次为全能铁甲/金星>莱砧1号/金星>黑籽南瓜/金星>圣砧1号/金星>大葫芦12号/金星>金星;全能铁甲/春秀>莱砧1号/春秀>圣砧1号/春秀>黑籽南瓜/春秀>大葫芦12号/春秀>春秀。综合考虑采用莱砧1号砧木嫁接对不同接穗而言均可较好的改善其对温度逆境的抵抗能力。更多还原

【Abstract】 In this reserch, the impact of root-knot nematodes and temperature stress for greenhouse grafted watermelon were studied. In order to clarify the root-knot nematode resistance mechanism, the grafted watermelon growth index and its physiological and biochemical changes were measured after nematode infection in greenhouse. The grafted watermelon growth index and its physiological and biochemical changes after temperature stress were also measured in order to clarify the temperature stress resistance mechanism. Two watermelon varieties,“jinxing”and“chunxiu”, were used as scion in this experiment;“bodajiajiewang”,“qingzhenyihao”,“black seed pumpkin”,“black pumpkin”,“bottle gourd”,“bigcalabash 12hao”,“baizisigua”,“quanengtiejia”,“laizhenyihao”and“shengzhenyihao”were used as rootstock. The main conclusions are as follows.1 Screening of watermelon rootstocksAs rootstock, laizhenyihao, black seed pumpkin, quannengtiejia, big calabash12hao and shengzhenyihao had better performance after a comprehensive analysis of the grafted survival, growth potential and fruit traits.2 Effects of root-knot nematode infection on grafted watermelon seedlingsAfter root-knot nematode infection, PAL activity, TAL activity, PPO, O2-.content, SOD and CAT activity and total phenol of grafted watermelon root were higher than self-root seedlings. Slightly difference were found in different rootstock scion combinations. After root-knot nematode infection, MDA content in root tissue continued to increase, but the increment of self-root seedlings was highest. In the 60 days after root-knot nematode infectted, gall index of grafted-root seedlings was lower than self-root seedlings. Nematode infection can lead to plant height, leaf number, leaf area, fruit weight, total sugar, VC and free amino acid content decreased; soluble protein content increased in watermelon.3 Effects of watermelon root exudates on root-knot nematode eggs hatchingNon-vaccinated nematode, the impact of self-rooted and grafted watermelon root exudates on root-knot nematode eggs hatching cuold be ignored. The root exudates of self-rooted watermelon, with root-knot nematode infection, had a clear stimulation to root-knot nematode eggs hatching. The root exudates of grafted watermelon, with root-knot nematode infection, had a significant inhibition to root-knot nematode eggs hatching.4 Effects of temperature stress on grafted watermelon seedlingsAfter heat stress, different scion and rootstock combinations showed different heat resistance capacity. In this study the sequence from high to low were shengzhenyihao/jinxing > laizhenyihao/jinxing > black seed pumpkin/jinxing>bigcalabash12hao/jinxing> quannengtiejia /jinxing > jinxing; shengzhenyihao/chunxiu > black seed pumpkin/chunxiu > big calabash12hao/chunxiu>laizhenyihao/chunxiu>quannengtiejia/chunxiu>chunxiu.After low temperature stress, different scion and rootstock combinations showed different cold resistance capacity. In this study the sequence from high to low were quannengtiejia/jinxing >laizhenyihao/jinxing>blackseedpumpkin/jinxing>shengzhenyihao/jinxing>bigcalabash12hao/jinxing>jinxing,quannengtiejia/chunxiu>laizhenyihao/chunxiu>shengzhenyihao/chunxiu>black seed pumpkin/chunxiu>big calabash12hao/chunxiu>chunxiu. The“laizhenyihao”was the best rootstock in this study through a comprehensive consideration. It can better improve the grafted watermelon resistance capacity to temperature stress.更多还原