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Resistance of Nine Wheat Cultivars and Lines to Greenbug, Schizaphis Graminum (Rondani) in Iran

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Resistance of Nine Wheat Cultivars and Lines to Greenbug, Schizaphis Graminum (Rondani) in Iran J. Agr. Sci. Tech. (2018) Vol. 20: 1173-1185 Resistance of Nine Wheat Cultivars and Lines to Greenbug, Schizaphis graminum (Rondani) in Iran M. Mohammadi Anaii1, M. Pahlavan Yali1*, and M. Bozorg-Amirkalaee2 ABSTRACT Greenbug, Schizaphis graminum (Rondani), is the main pest of wheat that can considerably limit profitable crop production, either through direct feeding or via transmission of plant pathogenic viruses. One of the most effective approaches of pest control is the use of resistant cultivars and lines. Based on the initial screening test of 35 wheat cultivars and lines, we selected five cultivars (Pishtaz, Omid, Yavaras, Akbari, and Bahar) and four lines (R1-10, R2-9, R3-16, and R3-17) with different levels of resistance to S. graminum for antixenosis and antibiosis experiments. In the antixenosis test, the number of S. graminum attracted on R1-10 was the lowest after 24, 48, and 72 hours. In life table study, S. graminum reared on Yavaras and R1-10 had the lower survival rate, fecundity, and reproductive period compared with other host plans tested. Values of the intrinsic rate of natural increase (rm), finite rate of increase (λ), net Reproductive rate (R0), and Doubling Time (DT) indicated lowest population growth of S. graminum, when fed on Yavaras (0.26 d-1, 1.30 d-1, 17.66 offspring and 2.62 days, respectively). Based on the antixenosis and antibiosis analyses in this study, we concluded that R1-10 and Yavaras were more resistant to S. graminum. These findings could be useful for integrated pest management of S. graminum in wheat fields. Keywords: Antixenosis, Antibiosis, cv. Yavaras, Integrated pest management, Pest control. INTRODUCTION yellow dwarf virus and maize dwarf mosaic (Nault and Bradley, 1969; Du et al., 2007). The greenbug, Schizaphis graminum Today, there is a great emphasis on (Rondani) (Hemiptera: Aphididae), is a application of non-chemical methods serious pest of small grains; especially together with selective pesticides in Downloaded from jast.modares.ac.ir at 14:51 IRST on Friday October 1st 2021 wheat, Triticum aestivum L. The greenbug programs of integrated pest management damage host plant by feeding on plant sap because of injurious effects of chemical directly and injecting toxic saliva into the pesticides on the non-target organisms and plant, which disturbs chloroplast and plant the environment. One of the most cell walls and subsequently reduces environmentally safe and economically photosynthesis (Yang et al., 2008; Najafi et efficient ways to control the pests is al., 2013). This pest, at the low density (15 utilization of resistant plant varieties (Papp aphids per plant), can decrease grain weight and Mesterhazy, 1993; Arzani and Lapitan, up to 35-40% in winter wheat (Kieckhefer 2007). Resistant cultivars could synergize and Gellner, 1992). In addition, S. graminum the effects of pest-suppression strategies. is one of the most important aphid vectors of The defense of resistant plants from insect plant pathogenic viruses such as barley pests functions at a very basic level, disturbing the normal relationship of the pest _____________________________________________________________________________ 1 Department of Plant Protection, Faculty of Agriculture, Shahid Bahonar University, Islamic Republic of Iran. 2 Department of Plant Protection, Faculty of Agricultural Sciences, University of Mohaghegh Ardabili, Islamic Republic of Iran. * Corresponding author; e-mail: [email protected] 1173 ______________________________________________________________ Mohammadi Anaii et al. with its host plant (Teetes, 2007). However, cultivars and lines, chosen by an initial how the host plants influence the insect is screening test, to S. graminum under affected by the type of resistance, e.g. controlled conditions. Besides, we aimed to antixenosis (non-preference), antibiosis, or survey the attraction preference of S. tolerance (Teetes, 2007). Antibiosis affects graminum in a free-choice test, and also to the biology of the insect; so, pest number determine the life table parameters of this and the consequent damage are diminished aphid on wheat cultivars and lines in no- compared to that which would have choice test. happened, if the insect was on a sensitive crop variety. Antibiosis resistance frequently MATERIALS AND METHODS results in higher mortality or lowered longevity and reproduction of the insect (Painter, 1951; Kogan and Ortman, 1978; Plant and Insects Culture Teetes, 2007). The effect of host plant varieties on population growth This research was conducted in the characteristics of insects, especially aphids, greenhouse and a laboratory of plant have been studied by a lot of researchers protection department, Faculty of (Webster et al., 1987; Thackray et al., 1990; Agriculture, University of Shahid Bahonar, Ozder, 2002; Lage et al., 2004; Razmjou et Kerman, Iran. We used 17 wheat cultivars al., 2011; Tofangsazi et al., 2011; Ahmadi and 18 wheat lines in this study. The seeds and Safavi, 2013; Doryanizadeh et al., 2016; of tested plants were obtained from Tazerouni et al., 2016). Furthermore many Agricultural Research, Education, and studies have focused on the type and level of Natural Resources Center of Kerman, Iran, resistance to greenbug in wheat varieties. and were planted for breeding of aphid For example, some research regarded colony and conducting the experiments. The reproductive and developmental rates of two plants were reared in greenhouse conditions greenbug biotypes in relation to two wheat (25-35˚C, 65±10% RH and under the natural host resistance genes on four wheat light) and then were kept in a laboratory genotypes (Lazar et al., 1995), resistance condition (growth chamber) with 25±1˚C, modalities including antixenosis, antibiosis 60±5% RH and photoperiod of 16:8 hours and tolerance of different wheat varieties, (L:D). The aphids used in this investigation against S. graminum (Castro et al., 1998; were acquired from the aphid colony reared Downloaded from jast.modares.ac.ir at 14:51 IRST on Friday October 1st 2021 Akhtar and Mujahid, 2006; Mojahed et al. in the laboratory of Institute of 2012), and the demographic characterization Environmental Sciences, Hi-tech University of S. graminum on different wheat cultivars of Kerman, Iran. The aphids originally were and lines (La Rossa et al., 2002; Najafi et al. collected from alfalfa fields of Baft region, 2013; Mojahed et al. 2013). Secondary plant Kerman province, in September 2015. To chemicals could play an important role in establish a colony of S. graminum, nymphs chemical defense against pests. Among and adults of aphids were transferred to the these, phenolic compounds are one of the potted wheat plants (cv. Mahdavi) in the most key resistance factors of plants, above-mentioned conditions. To maintain a causing unfavorable effects on insect growth suitable aphid colony, some greenbugs were and feeding behavior (Cipollini et al., 2008; transferred from infested plants to new Wójcicka, 2010). young plants every week. After rearing the Resistant wheat cultivars could minimize aphid for several generations on the wheat initial infestation of S. graminum or limit its plant, adult apterous aphids were used in the population growth and in result be effective experiments. At first, we carried out a in reducing insecticide use. The present screening test based on the mean number of study was designed to compare the aphids per plant (14 days after infestation) antixenosis and antibiosis of the wheat and, therefore, nine wheat cultivars and 1174 Greenbug-Resistant Wheat Cultivars and Lines ___________________________________ lines, namely, Yavaras, Bahar, Akbari, per aphid were documented and then Omid, Pishtaz, R2-9, R3-17, R3-16, and R1- removed regularly until the death of the last 10 were selected for further investigations greenbug. The obtained data from this (antixenosis and antibiosis tests). experiment was used for assessing the life table parameters by Carey’s formula (Carey, 1993). Antixenosis Test The antixenosis test was conducted in a Determination of Total Phenolic growth chamber (25±1◦C, 60±5% RH, and 16 L:8 D using a completely randomized The amount of phenolic compounds in design. Seeds of nine wheat cultivars and leaves of wheat cultivars and lines was lines tested were randomly planted in a measured based on Ronald and Lamia circle into trays filled with a mixture of soil, (1999). A 0.1 mg sample of leaf was milled sand, and manure (2:1:1). At two-leaf stage in 95% ethanol and permitted to extract for of plants, 150 apterous viviparous adults 24-72 hours. Thereafter, to 1 mL of the were released at the same time in the center sample, 1.5 mL of 95% ethanol was added of each tray (held by a transparent plastic and made up to a volume of 5 mL with cage). The number of aphid attracted on distilled water. To this mixture, 0.5 mL of each wheat cultivar and line was counted 50% Folin’s reagent and 1 mL of 5% after 24, 48, and 72 hours. This experiment sodium carbonate was added and vortexed. was carried out in 10 replicates for every The mixture was kept in the dark for 1 hour. three times. Then, the absorbance was measured at 725 nm using a spectrophotometer (Ronald and Lamia, 1999). Antibiosis Test Prior to the antibiosis test, two adult Statistical Analysis apterous aphids were randomly selected from the stock culture and then were placed Data were assessed for normality with the on the leaf of each plant of wheat cultivars Kolmogorov-Smirnov test. Variables were and lines studied. Each plant was covered evaluated using the one-way analysis of with cylindrical plastic cage (6 cm in variance in SPSS version 22.0 (SPSS, 2016). Downloaded from jast.modares.ac.ir at 14:51 IRST on Friday October 1st 2021 diameter and 30 cm in height) to prevent The Jackknife technique was used for parasitism and escape of aphids. A suitable estimating the variance of the life table hair brush was used for transferring aphids parameters (Maia et al., 2000).
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