ABSTRACT
Rind color and pattern are important external fruit quality traits of watermelon influencing the consumer attention and market acceptance. Varying degrees of green and yellow colors in different combinations forming distinct patterns have been observed on watermelon rind. In the current experiment, an attempt has been made to map the QTLs/genes for four important rind traits, namely, stripe color, stripe pattern, interstripe color, and interstripe pattern. The experiment consisted of two mapping populations namely F2 (Pop I) and BC1F2 (Pop II) derived from two parental lines, viz., BIL-53 (characterized by medium green marbled rind pattern and yellowish white blotchy interstripe pattern) and IIHR-140-152 (characterized by dark green solid stripes and greenish wavy interstripe pattern). Linkage mapping identified consistent QTLs across populations on chromosome 9. Comparative genomic analysis of these regions revealed two genes, namely, Cla97C09G175170 and Cla97C09G175150 as potential candidates for stripe and interstripe color. Sequence analysis of Cla97C09G175170 gene in parents along with reference genotypes, viz., 97,103 and Charleston gray suggests a 3 bp deletion on 11th exon to be associated with stripe color polymorphism in watermelon. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s13205-022-03112-7.
ABSTRACT
Association analysis was conducted in a core collection of 94 genotypes of Solanum pimpinellifolium to identify variations linked to salt tolerance traits (physiological and yield traits under salt stress) in four candidate genes viz., DREB1A, VP1.1, NHX1, and TIP. The candidate gene analysis covered a concatenated length of 4594 bp per individual and identified five SNP/Indels in DREB1A and VP1.1 genes explaining 17.0% to 25.8% phenotypic variation for various salt tolerance traits. Out of these five alleles, one at 297 bp in DREB1A had in-frame deletion of 6 bp (CTGCAT) or 12 bp (CTGCATCTGCAT), resulting in two alleles, viz., SpDREB1A_297_6 and SpDREB1A_297_12. These alleles individually or as haplotypes accounted for maximum phenotypic variance of about 25% for various salt tolerance traits. Design of markers for selection of the favorable alleles/haplotypes will hasten marker-assisted introgression of salt tolerance from S. pimpinellifolium into cultivated tomato.
