Study in Indian Cherry (Cordia myxa L.) against Dictyla cheriani Drake (Hemiptera: Tingidae) in Arid Region of Rajasthan

Twenty two germplasm accessions of Cordia myxa were collected from Rajasthan and established at the field gene bank for the study with regards to conservation, evaluation and resistance. The study was conducted to identify resistant accessions of Indian cherry and its association with morphomatric and biochemical traits. Based on Kaiser Normalization method, the germplasm accessions of Cordia myxa  categorised as AHCM-22-1, AHCM-25 and AHCM-34 were found to be resistant; AHCM-14, AHCM-30, AHCM-31, AHCM-03 and AHCM-11 were found moderately resistant; whereas AHCM-16, AHCM-09, AHCM-29 and AHCM-04 were found to be moderately susceptible; AHCM-33, AHCM-08 AHCM-07 and AHCM-06 susceptible and AHCM-01, AHCM-26, AHCM-24and AHCM-32 highly susceptible germplasm accessions. The per cent leaf infestation was the highest in AHCM-32 (68.51 %) and the lowest in AHCM-22-1 (12.26 %) followed by AHMM/BR-8 (14.11 %). The leaf infestations ranged from 12.26 to 68.51 % and were significantly lower in resistant germplasm accession and higher in susceptible germplasm accession. The significant positive correlation (r = 0.965) was observed between per cent leaf infestation and tingid bug population per leaf. Free amino acid had positive correlation with percent leaf infestation (r=0.955) and was found the lowest in the resistant accession and the highest in the susceptible accession, whereas phenols (r= -0.865), tannin (r= -0.942), total alkaloids (r= -0.976) and flavonoid (r= -0.982) contents had significant negative correlation with percent leaf infestation and the highest in resistance and the lowest in susceptible accession. The percent leaf infestation had significant negative correlation with length of leaf (r= -0.868) and width of leaf (r= -0.835). Leaf size, leaf roughness and leaf hairyness were found large, high rough and high hairy, respectively in resistant accession of Indian cherry. The one principal component (PCs) was extracted explaining cumulative variation of 90.07% in tingid bug infestation. The flavonoid, total alkaloid, tannins, phenols content, leaf length, width, roughness and hairyness were the novel antibiosis and antixenotic characters found in Indian cherry which were resistant to D. cheriani.