ABSTRACT
Arcelin, the antimetabolic protein from wild pulses is a known natural insecticidal molecule. Wild pulses with high arcelin content could serve as potential source to increase the levels of insect resistance in cultivated pulse crops. In this study, arcelin (Arl) gene expression was screened in seven stored product insect pest resistant wild pulse varieties using real time RT-qPCR. Arcelin gene specific real time PCR primers were synthesized from arcelin mRNA sequence of the wild pulse variety, Lablab purpureus. The results revealed different levels of arcelin gene expression in the tested varieties. Canavalia virosa registered significantly high content indicating its suitability for utilization of arcelin gene in developing stored product insect pest resistance with other cultivated pulses.
Subject(s)
Animals , Coleoptera/physiology , Canavalia/genetics , Canavalia/parasitology , Disease Resistance/genetics , Fabaceae/classification , Fabaceae/genetics , Fabaceae/parasitology , Gene Expression Regulation, Plant , Glycoproteins/genetics , Host-Parasite Interactions , Phaseolus/genetics , Phaseolus/parasitology , Plant Diseases/genetics , Plant Diseases/parasitology , Reverse Transcriptase Polymerase Chain Reaction/methods , Seeds/genetics , Seeds/parasitology , Species SpecificityABSTRACT
Potato crops are susceptible to various insect pests including the aphid Myzus persicae (Hemiptera, Aphididae) and the beetle Diabrotica speciosa (Coleoptera, Chrysomelidae). Induced resistance through silicon treatment of plants represents a potential strategy in pest management. The objective of the present study was to evaluate the effects of silicic acid on the development, productivity and level of infestation by beetles and aphids following foliar application to potato plants cultivated in the presence of organic compost or chemical fertiliser. Four experimental groups were studied, namely, plants cultivated in soil supplied with organic compost (30 t/ha) and either treated or non-treated with 0.5 percent silicic acid, and plants cultivated in soil supplied with NPK fertiliser (4:14:8; 4 t/ha) and either treated or non-treated with 0.5 percent silicic acid. The number of aphids and beetles detected on the leaves and the number of lesions caused by the beetles were evaluated. The height and the stem diameter of the plants were determined 60 days after the emergence and the productivity was determined 95 days after the planting of the seed potatoes. The results demonstrated that there were no interactions between silicic acid treatment and way of cultivation. Moreover, the incidence of beetles and aphids was not influenced by weekly application of silicon, and neither were the development and the productivity of plants. Although the development and productivity of organically cultivated plants were inferior to those grown in the presence of chemical fertiliser, plants cultivated on organic compost were less susceptible to attack by beetles.
A cultura da batata é suscetível a diversos insetos-praga, incluindo os pulgões (Hemiptera: Aphididae) e a vaquinha Diabrotica speciosa (Coleoptera: Chrysomelidae). A indução de resistência, por meio do tratamento com silício, é uma das táticas usadas no manejo integrado de pragas. Objetivou-se, no presente trabalho avaliar o efeito da aplicação foliar de ácido silícico sobre o desenvolvimento, produtividade e grau de infestação por pulgões e vaquinhas, em batateiras cultivadas em composto orgânico ou fertilizante químico. Foram testados quatro tratamentos: plantas cultivadas em solo suplementado com composto orgânico (30 t/ha) (tratadas e não tratadas com 0,5 por cento de ácido silícico) e plantas cultivadas em solo suplementado com fertilizante NPK (4:14:8; 4 t/ha; tratadas e não tratadas com 0,5 por cento de ácido silícico). O número de pulgões e vaquinhas observados nas folhas, assim como o número de lesões causadas pelas vaquinhas, foi determinado durante o desenvolvimento das plantas. A altura e o diâmetro da haste foram determinados 60 dias após a emergência das hastes, enquanto a produtividade foi determinada 95 dias após o plantio da batata-semente. Pelos resultados demonstrou-se que não houve interação entre a aplicação de silício e o tipo de cultivo. Além disso, a incidência de vaquinhas e pulgões não foi influenciada pela aplicação foliar semanal de silício, bem como o desenvolvimento e produtividade da cultura. Embora o desenvolvimento e produtividade das plantas cultivadas na presença de composto orgânico tenha sido inferior àquelas cultivadas em presença de fertilizante químico, as primeiras mostraram-se menos suscetíveis ao ataque das vaquinhas.
ABSTRACT
Analysis of antibiosis resistance to common cutworm (Spodoptera litura Fabricius) in soybean (Glycine max (L.) Merr.) has progressed significantly, but the immediate cause remains unknown. We performed quantitative trait loci (QTL) analysis of pubescence density and plant development stage because these factors are assumed to be the immediate cause of resistance to cutworm. The QTLs for pubescence appeared to be identical to the previously detected the Pd1 and Ps loci controlling pubescence density. We found no candidate loci for flowering time QTLs, although one could be identical to the gene governing the long-juvenile trait or to the E6 loci controlling maturity. None of the QTLs overlapped with the QTLs for antibiosis resistance.