Resistance of citrus genotypes to Phyllocnitis citrella Stainton (Lepidoptera: Gracillariidae)

Abstract

The development and reproduction of the citrus leafminer (CLM), Phyllocnistis citrella Stainton, were evaluated in six citrus genotypes in order to identify genotypes with resistance traits that could be applied in a program for the development of citrus varieties resistant to the citrus leafminer. Tests were conducted under controlled laboratory conditions (25  1ºC, 70  10% RH, and 14h photophase). Seedlings of each genotype tested were infested with eggs obtained from a stock colony of CLM maintained on 'Cravo' lemon (Citrus limonia L. Osbeck), and the duration and survival of the eggs, larval and pupal stages, pupal size and weight, fecundity and longevity of adults, and sex ratio were evaluated. No in luence was observed on the duration and survival of eggs, larvae and pupae of P. citrella. However, pupae obtained in the hybrid C x R 4 were signi icantly smaller and lighter than pupae from the remaining treatments. Adult females from the hybrids C x R 4 and C x R 315 were the least fecund. However, the lowest value for the corrected reproductive potential (CRP) was recorded in the hybrid C x R 315 , suggesting that this genotype is the least favorable for the development and reproduction of CLM. On the other hand, the highest CRP value obtained in the 'Rugoso' lemon con irms the susceptibility of this genotype, indicating it as the most suitable for CLM.

Characterization of tolerance to citrus leafminer of Citrus and related genera

“…According to Strauss and Agrawal (1999), the mechanisms underlying tolerance may differ according to the feeding mode of herbivores as, for example, in cotton plants (Gossypium hirsutum) that showed increased branching in response to bud removal but decreased branching in response to aphid attack. Santos et al (2011) demonstrated that hybrids C × R 315 and C × R 4 have CLM resistance factors of the antibiosis type. Given that these hybrids are derived from the crossing C. sunki × P. trifoliata and that the latter, according to the genetic analysis performed by Bernet et al (2005), presents a resistance gene that causes antibiosis, it is inferred that this genetic basis of resistance may have been transmitted to the hybrids.…”

“…, along with Trifoliata Limeira (P. trifoliata), which was previously selected as resistant to CLM (Santos et al 2011) and Rough lemon (C. jambhiri Lush. ), which presents a typical susceptibility pattern.…”

“…Studies have been conducted to detect sources of resistance in Citrus genotypes and other related genera (Goane et al 2008;Santos et al 2011), and factors of resistance to P. citrella involving antibiosis and antixenosis mechanisms have been identified. However, no reports are currently available concerning the evaluation of resistance of tolerance type to P. citrella.…”

Investigation of the life history and infestation of Phyllocnistis citrella (Lepidoptera: Gracillariidae) on four different hosts

“…In a previous study on the resistance of certain commercial citrus cultivars to P. citrella in Pakistan, cultivars such as Kinnow showed a resistant response, whereas C. limetta Risso, C. meyeri Tanaka, C. paradisi, and "sweet lemon" (scientific name unknown) showed susceptible responses (Mustafa et al 2013). In another study (Santos et al 2011), six genotypes of different citrus plants were evaluated to determine the resistance level. Among the different genotypes, the pupae obtained in hybrid C × R 4 (C. sunki horticultural usage ex Tanaka × P. trifoliata) were significantly smaller and the lowest value of corrected reproductive potential was recorded in hybrid C × R 315 (C. sunki × P. trifoliata), suggesting that these genotypes are the least favourable for the development and reproduction of P. citrella, although there was no significant difference in the developmental periods of immature stages between the various citrus genotypes.…”