Determination of biochemical selection criteria for resistance to leaf miner in chickpea (Liriomyza cicerina Rond.)

In Mediterranean region, the chickpea leafminer, Liriomyza cicerina Rondani, is the main insect pest of chickpea (Cicer arietinum L.) which can reduce the seed yield by 30%. Options to overcome damage caused by the insect are chemical, biological and cultural practices and used durable resistant varieties as well. One of the most efficient, sustainable, and economical practices is used resistant varieties along with cultural methods. Also, it is important to understand the role of different morphological and biochemical components of chickpea associated with resistance. The present study was aimed to (i) introgression of resistance to leafminer from C. reticulatum Ladiz. to cultivated chickpea, (ii) to estimate inheritance for resistance leaf miner, and (iii) to determine potential agro-morphological and biochemical selection criteria for resistance to leaf miner. For this purpose, recombinant inbred lines (RILs) derived from interspecific crosses between C. arietinum (CA 2969, ♀) and C. reticulatum (AWC 602, ♂) were used. Trials were carried out in natural insect epidemic conditions in 2017 and 2018. In trials, 130 RILs, their parents and a genotype susceptible to leaf miner (Sierra with simple leaf) as control were used under field conditions. RILs were evaluated for resistance to leafminer using a 1-9 scale (For instance, 1 = no insect damage, 9 = 100% insect damage, etc.) when susceptible female parent and Sierra were moderately susceptible (70% insect damage). According to the field screening results, eight resistant and eight susceptible genotypes were grown under insect epidemic conditions in the field and non-insect conditions in the greenhouse in order to determine the biochemical (organic acids) selection criteria. Oxalic, malic, quinic, tartaric, citric and succinic acids were determined by HPLC in the green part of eight resistant and susceptible RILs. In general, the potential biochemical selection criteria were found to be higher in resistant RILs than susceptible RILs. Tartaric and malic acid concentrations were determined lower level in resistant RILs than that of susceptible RILs. However, succinic acid was higher in the resistant RILs than the susceptible ones. Results suggested that high level of succinic acid could be used as a potential biochemical selection criterion for resistance to leaf miner in chickpea breeding material. Also, it was concluded that leafminer resistant RILs similar to "kabuli" chickpeas with high-yield can be directly grown in the target environment. Results showed that superior lines were found for resistance to leafminer and agro-morphological traits indicating that introgression of resistance to leafminer from C. reticulatum to C. arietinum could be possible by using interspecific crosses. The inheritance pattern of resistance to leafminer in RILs was shown to be polygenic nature and governed by some minor recessive genes. Broad sense heritability was estimated to be relatively low level as h2= 30.87. According to the path analysis, it was found that the most direct effect on resistance to leaf miner had plant height, grain yield and growth habit. Three RILs were found to be "resistant" and 12 RILs were found to be "moderately resistant". Some of these were free from pigment with cream color grain, double pods and higher yields such as "kabuli" chickpea.