Efeito de temperaturas de armazenamento e de genótipos de feijoeiro sobre a resistência a Acanthoscelides obtectus (Say) (Coleoptera: Bruchidae)

Pereira

2010

Ciênc. agrotec.

RESUMODurante o armazenamento de grãos de feijão (Phaseolus vulgaris L.), o rendimento pode ser reduzido devido às infestações de carunchos como os da espécie Zabrotes subfasciatus (Bohemann, 1833) (Coleoptera: Bruchidae). O ataque desse inseto afeta diretamente a qualidade dos grãos, além de facilitar a entrada de patógenos, tornando-os inviáveis para o consumo e/o comércio. Com a finalidade de buscar uma estratégia alternativa para o controle deste caruncho, avaliou-se a possível resistência de linhagens quase isogênicas contendo arcelina, linhagens selvagens contendo arcelina e cultivares comerciais de feijoeiro, em laboratório (T= 25±2° C, U.R.= 70±10% e fotoperíodo= 12h). Foram utilizados frascos contendo 10 g de grãos dos genótipos, os quais foram infestados por uma semana com sete casais do caruncho. Vinte e um dias após a infestação, os grãos foram avaliados contando-se o número de ovos viáveis. A partir de 25 dias da infestação, os grãos foram observados diariamente avaliando-se o número e o peso dos insetos emergidos, a viabilidade larval, o ciclo biológico (ovo-adulto) e o peso de grãos consumidos. Empregou-se um delineamento inteiramente casualizado, com oito repetições. Os genótipos Arc.2, Arc.3, Arc.4, Arc.3S e Ipa 6 expressaram baixos níveis de não-preferência para oviposição e foram classificados como deterrentes. Os genótipos Arc.1S e Arc.1 expressaram elevados níveis de antibiose; Arc.2, Arc.3 e Arc.4 apresentam o mesmo mecanismo, porém, em níveis inferiores. Termos para indexação:Resistência de plantas a insetos, feijão armazenado, caruncho, antixenose, antibiose. ABSTRACTDuring the storage of bean grains (Phaseolus vulgaris L.), production may be reduced due to weevils attack such as the species Zabrotes subfasciatus (Bohemann, 1833) (Coleoptera: Bruchidae). This insect attack affects directly the quality of grain and facilitates the entry of pathogens, making them impractical for consumption and trade. In order to find an alternative strategy to control of this pest, we assessed the possible resistance of near isogenic lines containing arcelin, wild lines containing arcelin and cultivars, in laboratory (T= 25±2° C, R.H.= 70±10% and photoperiod= 12h). The assays were conducted in vials containing 10g of bean grains per genotype, releasing seven pairs of the insect and maintaining the infestation during one week. Twenty-one days after the releasing, the grains were evaluated counting the viable eggs. Twenty-five days after the infestation, the evalutions were daily initiated, observing the number of adults emerged, larvae viability, development period (egg to adult) and weight of grains consumed. The assays were performed in a completely randomized design with eight replicates. The genotypes Arc.2, Arc.3, Arc.4, Arc.3S and Ipa 6 showed low levels of oviposition non-preference, being classified as deterrents. The genotypes Arc.1S and Arc.1 expressed high levels of antibiosis; Arc.2, Arc.3 and Arc.4 showed the same mechanism, however in lower levels.

Section: Resultsunclassified

Section: Introductionunclassified

Resistência de genótipos de feijoeiro a Zabrotes subfasciatus (Bohemann, 1833) (Coleoptera: Bruchidae)

Pereira

2010

Ciênc. agrotec.

“…Varieties Arc.1S and Arc.5S obtained the lowest number of eggs in tests with freshly harvested and 8-month-old seeds, respectively, indicating the occurrence of oviposition non-preference type of resistance. Variety Arc.1S had previously expressed this resistance mechanism in a study conducted by Baldin and Lara (2004), in which the influence of temperature on the resistance expression of bean varieties to A. obtectus was evaluated. The varieties × storage time interaction revealed a decrease in oviposition on the varieties as seeds became older.…”

Section: Discussionmentioning

confidence: 99%

“…After infestation, the containers were covered with a lid and taken to a BOD incubator (at the previously described environment conditions). The insects were removed after a 7-day infestation period (Baldin & Lara, 2004). Oviposition preference was evaluated using a stereoscopic microscope by counting the total number of eggs per variety after infestation for 20 days.…”

Section: Antixenosis And/or Antibiosis: Single Choice Testmentioning

confidence: 99%

“…Plant-, insect-, and environment-related factors might affect the resistance expression of varieties to insects in the field (Lara, 1991). However, during grain storage it is known that variations in light intensity and relative humidity (Tingey & Singh, 1979), in addition to increases or reductions in temperature (Baldin & Lara, 2004) might significantly affect the resistance expression of varieties against insects. However, little is known about the stability of varieties during different periods of storage.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Resistance of stored bean varieties to Acanthoscelides obtectus (Coleoptera: Bruchidae)

Lara

2008

Insect Science

Self Cite

During bean seed storage, yield can be lost due to infestations of Acanthoscelides obtectus Say, the bean weevil. The use of resistant varieties has shown promising results in fighting these insects, reducing infestation levels and eliminating chemical residues from the beans. The expression of resistance to A. obtectus in bean varieties is frequently attributed to the presence of phytohemagglutinins, protease inhibitors and alpha-amylase, and especially to variants of the protein arcelin, which reduce the larval viability of these insects. To evaluate the effect of bean seed storage time on the resistance expression of bean varieties to A. obtectus, tests with seeds of three ages (freshly-harvested, 4-month-old, and 8-monthold) were conducted in the laboratory, using four commercial varieties: Carioca Pitoco, Ipa 6, Porrillo 70, Ônix; four improved varieties containing arcelin protein: Arc.1, Arc.2, Arc. 3, Arc.4; and three wild varieties also containing arcelin protein: Arc.1S, Arc.3S, and Arc. 5S. The Arc.5S, Arc.1S, and Arc.2 varieties expressed high antibiosis levels against the weevil; Arc.1 and Arc3S expressed the same mechanism, but at lower levels. The occurrence of oviposition non-preference was also observed in Arc.5S and Arc.1S. The Arc.3 and Arc. 4 varieties expressed low feeding non-preference levels against A. obtectus. The expression of resistance in arcelin-bearing, wild or improved varieties was affected during the storage of seeds, and was high under some parameters but low in others. The results showed that addition of chemical resistance factors such as protein arcelin via genetic breeding may be beneficial in improving the performance of bean crops.

Characterization of resistance to the bean weevil Acanthoscelides obtectus Say, 1831 (Coleoptera: Bruchidae) in common bean genotypes

Arthropod-Plant Interactions

Lara

Camargo

et al. 2017

Self Cite

The bean weevil Acanthoscelides obtectus (Say, 1831) (Coleoptera: Bruchidae) is one of the most serious pests of stored beans worldwide because of the damage it causes to grains within warehouses. The use of resistant genotypes may offer a control strategy for this pest. In the current study, we screened common bean genotypes of Andean American and Mesoamerican origin in laboratory and greenhouse bioassays to select the most promising beans for resistance to the bean weevil. In the laboratory, we evaluated number of eggs, period of development (eggadult), number of emerged adults, dry weight of adults, and weight of consumed grains. In the greenhouse, number of pods per plant and number of grains per pod were evaluated. We also assessed the percentages of damaged pods per plant and damaged grains per pod. Combining the results obtained in the laboratory and greenhouse assays, the common bean genotypes Arc.1, Arc.2, Arc.1S, Arc.5S, and Arc.3S were identified as resistance expressing antibiosis against A. obtectus. The lowest percentages of damaged pods were found in the Arc.1 and Arc.1S genotypes, and their resistance to damage was apparently morphological (antixenotic) because they possessed structures that prevented contact between larvae and grains. The use of resistant genotypes in combination with other techniques may improve management of the weevil. Additionally, the resistant genotypes identified here can be used in breeding programs to develop common bean lines with resistance to A. obtectus.