Naslov
Genomic changes associated with insecticide resistance in economically important insect pests in Croatia

Autori
Kadoić Balaško, Martina

Vrsta, podvrsta i kategorija rada
Ocjenski radovi, doktorska disertacija

Fakultet
Agronomski fakultet

Mjesto
Zagreb

Datum
16.12

Godina
2022

Stranica
132

Mentor
Bažok, Renata ; Lemić, Darija ; Mikac, Katarina M. ; van den Bergh, Geritt

Ključne riječi
single nucleotide polymorphism ; geometric morphometrics ; resistance ; resistance mechanism ; genetic structure ; genetic diversity ; population structure ; monitoring ; control strategies ; anti-resistance programs

Sažetak
According to some projections, there will be approximately 9.7 billion people on the planet by 2050. In order to continue to feed the world and meet the increasing demand for food by a growing population, yields of many important crops for human consumption must be increased. The emergence of resistance (pest resistance to control measures) is a serious and growing problem in agricultural production that significantly reduces yields. Without effective control, 70% of food is wasted. Western corn rootworm (Diabrotica virgifera virgifera LeConte) (WCR), Codling moth (Cydia pomonella L.) (CM), and Colorado potato beetle (Leptinotarsa decemlineata Say) (CPB) are the most important pests in Croatian agriculture, and these insects have developed resistance to various insecticides and established control strategies. There is a need to find effective methods for determining resistance that will allow early detection and the development and timely implementation of resistance control strategies. In this study, we used single nucleotide polymorphism (SNP) markers to perform a detailed population genetic analysis of the whole genome and geometric morphometric methods to analyze morphological variations related with resistance development. The aim of this dissertation was to analyze genetic structure, differentiation, gene flow, distribution and adaptability of the three mentioned pests by genotyping with the SNP method. In addition, morphometric analyzes were performed to determine the relationship between genetic mutations reflected into insect phenotype. For genetic analyzes, genomic DNA of WCR, CM and CPB was isolated and forewings (CM) or hindwings (WCR and CPB) were used for morphometric analyzes. All the data were analyzed in the statistical program R. Different approaches were used to analyze the genetic structure of WCR, CM and CPB populations: Bayesian-based model of population structure (STRUCTURE), principal component analysis (PCA), discriminant analysis of principal components (DAPC), neighborhood cluster analysis (NJ), and VanRaden Kinship matrix analyzes. To confirm the genetic results, forewing and hindwing morphology was examined using geometric morphometric techniques based on the venation patterns of 14 landmarks for WCR, 18 landmarks for CM, and 16 landmarks for CPB. The results for WCR indicated that the combination of genetic and geometric morphometrics could be a reliable technique to detect differences between WCR populations. The results also showed that geometric morphometrics can be used as a biomarker for resistance detection as part of a larger integrated resistance management strategy for western corn rootworm. For CM SNP markers did not show sufficient power to detect changes between CM populations related to the type of apple control method. However, geometric morphometrics showed higher sensitivity in detecting population changes associated with different types of apple production and proved to be a reliable, accurate, and cost-effective technique. For CPB populations, we found low genetic variability and the presence of a single panmictic population in the study area. The results of GM for the CPB populations allowed us to find morphological changes associated with geographical areas of Croatia and confirmed a low difference, while demonstrating phenotypic plasticity. The combined use of SNPs and geometric morphometrics to detect resistant variants is a novel approach where morphological traits can provide additional information about underlying population genetics and morphology can contain useful information about genetic structure. It also provided new insights into an important and timely area of pest management, on how to prevent or delay the development of resistant populations to minimize the negative effects of resistance.

Izvorni jezik
Engleski

Znanstvena područja
Poljoprivreda (agronomija)

POVEZANOST RADA