| Oat not only is an important crop of rear and grain, but also a crop of green nutrition and health. Aphid is one of the important pests which feeding on oat. In recent years, occur and damage of aphid have aggravated with the change of climate. The status at home and overseas what have studied on oat and its pests were summarized in this paper; The species and dynamic of aphid and its primary natural enemy were systemic investigated in Linxia and Lanzhou area, Gansu province respectively, and the other pest species which can jeopardize on oat were investigated; At the same time, the resistance of different oat varieties to aphid was studied in field and indoors respectively.1. Investigation on species and dynamic of aphid and its natural enemy and other pest speciesThe investigation results showed that the aphid species which feeding on oat were Macrosiphum. avenae (Fabricius), Rhopalosiphum. padi Linnaeus,Acyrthosiphon. dirhodum (Walker) and Schizaphi. graminum Rondani. Their occur period and feeding part on oat were different, Rh. padi Linnaeus's occur period was prior to other aphids, it mostly feeding on the lower sheath and stalk of oat ; A. dirhodum Walker's number was gradually increasing with the hoist of air temperature, it mostly feeding on the obverse and inverse of oat leaf. The number of M. avenae Fabricius was gradually increasing after oat tasseled, and reached the maximum during oat milk-filling stage; Sch. graminum Ronda's number was very little, only was found on summer stubble oat.In oat field, twenty-eight of aphid natural enemies were observed, pertain to Coleoptera,Hemiptera,Neuroptera,Hymenoptera,Diptera, 19 families of Insecta and Araneae of Arachnida respectively ;The other pests have 9 families, pertain to Coleoptera,Homoptera and so on. The occurred number of aphid and natural enemies had obvious follow phenomenon, pinnacle period of natural enemy lagged the aphid's 7 to10days.2. Study on resistanceThe resistance of different oat varieties to aphid was appraised with the method of aphid injury index in field. The results showed that the resistance of different oat varieties to aphid had distinct (P<0.05)or utmost distinct difference(P<0.01), Baiyan No3 was immunity variety; Qinghai 444 and Baiyan No4 etc. were high resistant varieties; Pauc, Baiyan No6 and other seven varieties were medium resistant varieties; 9401-2-1 and other three varieties were resistant varieties; Qingyin No1,Qingyin No2 etc. were susceptive varieties; Caoba No1 was high susceptive variety.The resistance of Qingyin No1, Qingyin No2, Qinghai444, Janadazaipeiyanmai and Qinghaitianyanmai were evaluated by founding experimental population life table of aphids indoors. The results indicated that the larval survival rates and winged rates of three aphids on five oat varieties had significant difference. The average winged rates of M.avenae ,Rh.pddi and Ach.dirhodum were 8% ,14% and 6% separately .Only individual larval growth period of three aphids had difference on five oat varieties. The preoviposition period, life-span and mean fecundity of Rh.padi had significant difference among five oat varieties. The preoviposition period, life-span and mean fecundity of M.avenae and A.dirhodum hadn't difference.The net reproduction rates (Ro), intrinsic rates (rm), mean generation times (T), finite increase rates (λ) of three aphids on five oat varieties had significant difference.A. dirhodum (Walker) was predominance aphid species in field, only chose the net reproduction rates of A. dirhodum (Walker) to estimate the resistance of five oat varieties in indoor, in order to compare with the result of field resistance. The resistance order of five oat varieties indoors from high to low was Qinghai444 > Qinghaitianyanmai >Jianadazaipeiyanmai>Qingyin No1>Qingyin No2. As a result of the difference of field and indoor circumstance,resistance appraise method,resistance mechanism of adult plant and young plant, the result of indoor resistance was not completely consistent with the result of field resistance.
|
PDF Full Text Request