QTL mapping for yield traits in vegetable cowpea

The F4 population comprising of 92 plants descended from the cross of semi-trailing, medium-long podded, low yielding cv. Kanakamony [Vigna unguiculata (L.) ssp. cylindrica] with pole type, long podded, high yielding cv. Sharika [V. unguiculata. ssp. sesquipedalis] was used for mapping the yield-related traits in vegetable type cowpea. Using 30 polymorphic SSR markers, a linkage map spanning 908 cM with two linkage groups (LG1 with eight markers spanning 637 cM and LG2 with five markers spanning 271 cM) was constructed. CLM0083 was an anchored marker for pod weight and total dry pod yield. For days taken for the first flowering, LG1 and LG2 had four and three hotspots, respectively. SMA confirmed that CLM0177 on LG1 and CLM0300 are anchored markers for this trait. For branch number, a hotspot was found on LG2 between CLM0200 and CLM0088. SMA confirmed the linkage of CLM0200 with this trait. For root length, a hotspot was found between CLM0244 and CLM0008 on LG1. On LG2, the hotspots were present between CLM0200 and CLM0088, and between CLM0260 and CLM0218. SMA confirmed the linkage of CLM0201, CLM0244 and CLM0300, with this trait. For plant height, a hotspot existed between markers CLM008 and CLM177 on LG1. For plant weight, a hotspot with anchored marker CLM0244 and flanking markers CLM0186 and CLM0008 was found on LG1. The region 24.25-126.86 cM on LG1, bracketed by CLM0244 and CLM0177 and with an anchored marker CLM0008, had QTL hotspots for days taken for first flowering, total dry pod yield, root length, plant height and plant weight.