Identification of resistance against Sorghum aphid (Melanaphis sacchari (Zehntner)) and plant height characteristics via molecular markers in a sorghum (Sorghum bicolor (L.) Moench) collection

Wide adaptation to different climatic and environmental conditions, effective water consumption and high amount of biomass production make sorghum a potential crop for bio-energy. The positive effect of tall plant height on biomass and the negative impacts of biotic and abiotic stresses on production give direction to the sorghum breeding purposes. From this point of view, sorghum collection consisting of 561 accessions originating from all over the world was screened with molecular markers in order to identify resistant individuals against to aphid. Visual scorings were also performed at field conditions of two locations, Konya and Antalya. Aphid species were diagnosed using samples obtained from those locations. In addition, plant height observations were performed in two locations (Antalya and Konya) for two subsequent years (2013 and 2014). Moreover, plant height was characterized at DNA level using leaf samples of each accession collected from both locations. PCR products of four SSR markers associated with plant height characteristics in sorghum were separated in agarose gels and visualized under UV light. Amplified products were also analyzed with the Fragment Analyzer™ which is of high resolution bio-imaging system. In 2013, 353 genotypes were determined as a tall plant height while 196 were short at Antalya. In 2014, plant height observations were performed using 53 genotypes and 9 standard cultivars that were selected according to the agro-morphological, technological and molecular data obtained in 2013. In 2014, 57 and 5 genotypes were identified as a tall and short, respectively at Antalya location while 52 and 10 genotypes were defined as a tall and short, respectively in Konya. Molecular analyses indicated that 91 genotypes were found to be resistant to Melanaphis sacchari. 27 of these resistant genotypes provided by USDA were predominantly originated from Etiyopya. 61 genotypes also obtained from ICRISAT were mostly from South Africa, Swaziland and Lesotho. Rest three genotypes were registered varieties of Turkey. Based on visual scorings, 19 genotypes and 2 registered varieties grown in Antalya were potentially tolerant to Rhopalosiphum maidis which were epidemic at Antalya location. In Konya location, two genotypes were found to be possible tolerant to Rhopalosiphum padi. Above all, BSS507 was the only genotype which was resistant to aphids based on the data acquired from Antalya and Konya as well as molecular analysis.