Oviposition preference and larval performance of sugarcane borer in eight sugarcane genotypes

Abstract

The sugarcane borer Diatraea saccharalis Fabr. (Lepidoptera: Crambidae) is one of the most important pests of sugarcane in the Americas. The purpose of this study was to assess multiple resistance traits in eight sugarcane genotypes against D. saccharalis, including five commercial cultivars and three exotic germplasm with potential to serve as resistance sources against this pest. The oviposition preference was assessed by using both free-choice and non-choice tests. The performance of both early stage larvae feeding on the leaves and late stages larvae feeding within the stalks were also assessed. There were differences among genotypes for number of both eggs and egg cluster in the free-choice test while no differences in non-choice test were observed. There were also differences in survival of early stage larvae feeding on the leaves, foliar injury rating and stalk damage. The genotype IM76-228 was the least preferred for oviposition and it seems that leaf width had some influence on adults' preference rather than greening of the leaves. IM76-228 and RB867515 causes higher mortality of early stage larvae feeding in the stalks while IM76-228 and RB985523 had lower damage in both leaves and stalks. The genotype IM76-228 was the most resistant to D. saccharalis and could serve as genes sources for resistance in sugarcane breeding programs.Index terms: Saccharum spp.; Diatraea saccharalis; host-plant resistance. RESUMOA broca da cana-de-açúcar Diatraea saccharalis Fabr. (Lepidoptera: Crambidae) é uma das mais importantes pragas da cana-de-açúcar nas Américas. Este estudo foi realizado para investigar múltiplos traços de resistência em oito genótipos de cana-de-açúcar contra D. saccharalis, incluindo cinco cultivares comerciais e três germoplasmas exóticos com potencial para servir de fontes de resistência contra esta praga. A preferência de oviposição foi avaliada por meio de testes de escolha livre e de não-escolha. O desempenho de larvas de estágio inicial que se alimentam das folhas e de larvas de estádio tardio alimentando-se com os colmos também foi avaliado. Houve diferenças entre os genótipos para o número de ovos e posturas no teste de livre escolha, enquanto não foram observadas diferenças no teste de não-escolha. Houve também diferenças na sobrevivência de larvas de estádios iniciais que se alimentam das folhas, índice de lesões e dano no colmo. O genótipo IM76-228 foi o menos preferido para a oviposição e parece que a largura da folha teve alguma influência sobre a preferência dos adultos em vez da intensidade de verde das folhas. IM76-228 e RB867515 provocaram uma mortalidade mais elevada de larvas de estádio inicial alimentando-se dos colmos, enquanto que IM76-228 e RB985523 apresentaram menor dano nas folhas e nos colmos. O genótipo IM76-228 foi o mais resistente a D. saccharalis e pode servir como fonte de genes para resistência em programas de melhoramento de cana-de-açúcar.Termos para indexação: Saccharum spp.; Diatraea saccharalis; resistência de plantas hospedeiras.

Genetic parameters and selection of sugarcane in early selection stages for resistance to sugarcane borer Diatraea saccharalis

“…Sugarcane resistance to borer is the sum of several genes that confers the trait of some resistance. Several resistance traits in Brazilian sugarcane genotypes, such as antibiosis and antixenosis, have been reported (Dinardo-Miranda et al 2012, Pimentel et al 2017. Our results also show the high genetic variability for borer resistance in Brazilian sugarcane populations.…”

“…Previous studies have demonstrated that some sugarcane genotypes in Brazil have genes that confer some degree of resistance to D. saccharalis. This resistance is due to the presence of some leaf component that causes higher mortality of early-stage larvae, some barrier on the stalk surface that hinders or delays larvae penetration within the stalks, or some trait within the stalks that reduces larval feeding and/or affects larval performance (Dinardo-Miranda et al 2012, Pimentel et al 2017. Resistance genes are likely to provide more durable protection than that conferred by Bt genes.…”

Resistance to Diatraea (Lepidoptera: Crambidae) stem borers in sugarcane is independent of species

“…These conditions present challenges that may affect trial observations (Smith 2005) including controlling pest density, environmental conditions, and natural enemies. Therefore, several authors have used plant or stalk infestations under confined conditions (Dinardo-Miranda et al 2012, Vieira et al 2017, Rea et al 2018) or in bioassays where sugarcane tissue is provided in meridic diets to establish the precise impact of a specific sugarcane genotype on pest development (Taneja and Nwanze 1990, Meagher et al 1996, White et al 2011).…”

Genetic parameters and selection of sugarcane for borer resistance in the advanced selection stage

“…Several resistance mechanisms against the sugarcane borer have been reported in sugarcane genotypes, including a low preference for oviposition, high mortality of early-instar larvae, the difficulty of larvae entering the stalks, and lower larvae development within the stalks (Pimentel et al 2017). In addition, differences among genotypes are often reported in field trials for several resistance traits, such as the percentage of bored internodes or internodes with exit holes, percentage of bored stalks, pupation success, estimates of adults produced per area/year/ variety, and the damage rating (Bessin et al 1990, White 1993, White et al 2011, Milligan et al 2003, Nibouche and Tibere 2008, Nikpay 2016.…”