Morphological and genetic diversity studies among populations of tea mosquito bug, Helopeltis theivora from Assam, India

Abstract

Multilocus DNA fingerprinting and morphometry were compared to evaluate genetic diversity of tea mosquito bug, Helopeltis theivora Waterhouse (Hemiptera: Miridae). Eighty-one female individuals representing 27 populations of H. theivora from tea plantations of different regions of Assam, India were collected and evaluated. Observation of 12 characters i.e. body length, antennae length, head width, stylet length, thorax width, forewing length, forewing width, hind wing length, hind wing width and length of foreleg, middle leg, hind leg revealed distinct pattern in different population of H. theivora. On the basis of morphological traits, six different types of population groups have been identified. Genetic analysis produced a total number of 262 bands, of which 221 (84.35 %) were polymorphic. The number of bands produced per primer varied from 2 to 17. The dendrogram derived from UPGMA cluster analysis indicates three clusters containing 24 populations at 63 % of similarity while three populations viz. H23, H19 and H14 excluded from the major cluster and come out as a discrete cluster. The cluster 1 includes populations from 9 different districts of Assam, cluster 2 again included 5 populations, cluster 3 constitute 3 populations and cluster 4 again consist of 3 populations. Both marker (morphological and molecular) systems indicated that genetic variability within populations examined was significantly high. Appropriate quality and quantity of chemical pesticides used in pest control programmes is a fundamental goal in the tea industry. It is supported by the knowledge of patterns of population connectivity and historical demography.

Evaluation and Validation of Reference Genes for Quantitative Real-Time PCR in Helopeltis theivora Waterhouse (Hemiptera: Miridae)

“…theivora take in the plant juice from young buds, leaves, fruits and shoots with their piercing-sucking mouthparts 25 . As a consequence, drying up of shoots and fruits can arise from their sucking behavior, which causes more than 25% of crop losses 26,27 . In addition, this pest demonstrates high persistence of populations against stressful environment through strong ability of adaptation.…”

Evaluation of Resistant Tea (Camellia sinensis L.) Clones Against Helopeltis bradyi

“…This result indicated that trichomes did not significantly affect the reduction of Helopeltis damage in tea clones. Helopeltis has long styles measuring 1.5-2.1 mm (Bhau, Mech, Borthakur, Bhuyan, & Bhattacharyya, 2014). Trichomes did not sufficiently prevent a Helopeltis attack in the bottom part of the leaves because tea leaves have trichomes in the bottom part, while Helopeltis attack the upper surface of leaves.…”

Research Article A RAPD-PCR-based genetic diversity analysis of Helicoverpa armigera and H. zea populations in Brazil.

“…One of these strategies is the PCR-based randomly amplified polymorphic DNA (RAPD), which is a type of polymerase chain reaction where the fragments of DNA are randomly amplified, using short synthetic oligonucleotides of random sequence (Williams et al, 1990). The RAPD marker system has many advantages, including the low cost, little technical demands, and no prior knowledge about DNA sequence (Bhau et al, 2014). Besides, according to Anbalagan et al (2012), RAPD marker system is suitable for studies of population structure because it allows for the detection of polymorphisms in coding and non-coding regions of both nuclear and mitochondrial genomes.…”