Identification of Mexican lemon hybrids using molecular markers SSR

Abstract

The development of tolerant varieties can help to confront and reduce the impacts of diseases that threaten the cultivation of Mexican lemon [Citrus aurantifolia (Christm) Swingle]. Hybrid interspecific and intergeneric plants have been generated in search of genotypes with resistance or greater tolerance to VTC, HLB and anthracnose. Because most citrus fruits are apomictic and polyembryonic the identification of hybrid plants is required by techniques such as molecular genetic markers. The objective of the study was to identify Mexican lemon hybrids using molecular markers called microsatellites (SSR). A population of 203 individuals of crosses carried out from 2009 to 2012 was used in the INIFAP-Tecoman Experimental Field. The genomic DNA was made according to the CTAB 2% method. The PCR reaction was done with a volume of 20μl containing 10 μl of iTaq™ Universal Probes supermix and 2.5 μl of each Forward and Reverse primer. The primers used were TAA41, TAA45, cAGG9 and TAA52. The amplified products were analyzed in 8% polyacrylamide gel and stained with 0.2% silver nitrate. The identification of hybrid plants was carried out by comparing the bands produced by the hybrids with those of the parents. The four initiators allowed the identification of hybrid plants. The highest number of identified plants was obtained with primers TAA45 and cAGG9 with 145 and 130 respectively. The identification of the hybrids of the population under study through the analysis of molecular markers, will allow genetic improvement programs to be efficient, which implies obtaining a large number of seedlings derived from the crosses made.