4个苜蓿品种对两种体色豌豆蚜的抗生性

Antibiosis of four alfalfa cultivars against two color morphs of Acyrthosiphon pisum

在抗蚜鉴定的基础上,在室内20℃条件下,选用4个抗蚜性不同的苜蓿品种,测定了不同苜蓿品种上两种体色豌豆蚜的生物学参数。结果显示,两种体色豌豆蚜在‘金皇后’上的发育历期、净生殖率、平均世代周期差异显著(P<0.05),绿色豌豆蚜若虫的发育历期长于红色型,而红色豌豆蚜的净生殖率、平均世代周期大于绿色型;在‘甘农5号’上两种色型豌豆蚜的内禀增长率、周限增长率、种群加倍时间差异显著(P<0.05),绿色豌豆蚜的内禀增长率、周限增长率高于红色型,种群加倍时间低于红色型。以内禀增长率作为测定抗生性的指标,4个苜蓿品种对两种色型豌豆蚜的抗性表现不同,其中‘金皇后’对绿色豌豆蚜的抗性较高,‘甘农5号’对红色豌豆蚜的抗性较高,‘猎人河’对两种色型豌豆蚜的抗性均较低,4个苜蓿品种对绿色豌豆蚜抗性的大小顺序为‘金皇后’>‘甘农5号’>‘甘农3号’>‘猎人河’,对红色豌豆蚜抗性大小依次为‘甘农5号’>‘甘农3号’>‘金皇后’>‘猎人河’。

The biological parameters of two color morphs of pea aphids （Acyrthosiphon pisum） on four cultivars of alfalfa （Medicago sativa Linn. ） were evaluated at 20 ℃ under laboratory conditions in order to identify the antibiosis of alfalfa cultivars against two color morphs of pea aphids. Two color morphs of pea aphids were significantly different in mean developmental time, net reproductive rate, mean generation time on ＇ Golden Empress＇. The mean developmental time of green nymphs of pea aphids was longer than that of red nymphs, while the net reproductive rate and mean generation time of red pea aphids were greater than those of green pea aphids. In contrast, two color morphs of pea aphids were significantly different from each other in the intrinsic rate of increase, population doubling time, and infinite rate of increase on ＇Gannong No. 5＇. The population doubling time of red pea aphidswas significantly higher than that of green morphs, but the intrinsic rate of increase and infinite rate of increase of red pea aphids were significantly lower than those of green morphs. Using the intrinsic rate of increase （rm） as the index of alfalfa antibiosis to the aphids, the four alfalfa cultivars were different in their antibiosis against the two color morphs of pea aphid. The resistance of ＇Golden Empress＇ to green morphs was higher than that of other cultivars; on the contrary, the resistance Of ＇Gannong No. 5＇ to red aphid was higher, while resistance of ＇ Hunter River＇ against two color morphs of pea aphid was lower. The levels of alfalfa resistance to green and red aphids were in the order from high to low as followed：＇ Golden Empress＇, ＇ Gannong No. 5＇, ＇ Gannong No. 3＇ and＇ Hunter Rive＇, and ＇Gannong No. 5＇, ＇Crannong No. 3＇, ＇Golden Empress~ and ＇ Hunter River＇, respectively.