不同甘薯品种小象甲的危害比较及相关性分析

选取福薯8号、金山57、泉薯12号等8个不同的甘薯种质,按随机区组排列连续3年种植在同一甘薯小象甲危害较重的地块,在收获前通过对象甲危害指数、产量损失率、拐头(薯蒂)危害率等3项指标调查和鉴定,结合品质检测和田间降水量统计开展各指标间的比较和相关性分析。结果表明:以危害指数为主要指标,从高到低依次是金山57、福薯8号、广薯87、泉薯12、福薯88、福薯90、福薯9号、福薯2号,其中金山57的危害指数最高,受危害最重,产量损失率也较高,后面的品种依次降低,综合危害指数、拐头危害率和产量损失率发现,金山57、福薯8号2个品种遭受小象甲的危害最重,而福薯2号遭受小象甲危害的程度最低;不同年份间小象甲对甘薯的危害指数、拐头侵染率和产量损失率之间均达到极显著差异,其中产量损失率与危害指数相关性最高,拐头侵染率与危害指数相关性中等,拐头侵染率与产量损失率相关性最低。3年的试验结果结合降水量、品质检测结果分析表明,象甲发生较重的丘陵地区,天气持续干旱少雨是造成甘薯象甲大面积爆发的重要因素,甘薯的某些品质相关性状如维生素和氨基酸含量与小象甲危害的3个指标中的2个指标达到显著性相关。

Correlation Among Criteria for Evaluating Damages on Varieties of Sweet Potatoes by Cylas formicarius (F.)

Eight sweet potato varieties (including Fushu 8,Jinshan 57,Quanshu 12,etc.)of varied qualities were used for comparison in this study.For 3 consecutive years,they were planted with a randomized block design and grown at a same location,where a severe Cylas formicarius (F.)infestation existed.The damage index,tuber yield reduction and infection rate on the sweet potato stalks were monitored and confirmed prior to harvesting. Variance and correlation analyses were conducted along with tests on plant qualities.The results showed that the damage index rated the cultivars in the order of Jinshan 57>Fushu 8>Guangzhou 87>Quanshu 12>Fushu 88>Fushu 90>Fushu 9>Fushu 2. Jinshan 57 suffered the most serious harm among all,and its tuber yield reduction was also among the greatest.Overall,Jinshan 57 and Fushu 8 encountered the heaviest damages by the infestation, while Fushu 2 the least.All 3 selected evaluation criteria showed extremely significant differences in the years of the survey.The damage index had the highest correlation coefficient with the tuber yield reduction,followed by the stalk infection rate,while that between the stalk infection and the tuber yield reduction rates the lowest.The statistical analysis suggested that those observations correlated significantly with the annual precipitation in the area, and that continued drought was the most important factor causing the outbreak of C.formicarius (F.)in a large area.In addition,a significant correlation was found between the nutritional quality and the damage index of the sweet potatoes due to C.formicarius (F.)infestation.