Abstract:
Improvement of yield, nut quality and plant size in cashew is a complex process through conventional technique. It takes at least 9-12 years to develop new varieties, this causes inadequate supply of improved planting materials to farmers. To overcome this limitation, we need to use marker-assisted selection. However, to date, MAS in cashew breeding has been hampered by the absence of markers linked to yield, nut quality and plant size. This study aimed at identifying quantitative trait loci associated with yield, nut quality and plant size. To map QTL a genetic linkage map with 761 single nucleotide polymorphism markers was developed using F2 population of cashew derived from ATA19/250 * Cook05. The linkage map consisted of 21 linkage groups covering 2230cM with an average marker distance of 3.3 cM. The F2 progenies were evaluated for yield, number of nuts, nut weight, number of kernels, kernel weight, plant size, canopy diameter and percentage outturn in three seasons namely 2013, 2014 and 2015. A total of 13 QTLs were mapped on 8 linkage groups which explained 25.6 - 56% of the total phenotypic variation. The identified QTLs will speed up the development of high-yielding varieties with good nut quality through marker assisted selection. |
