Abstract:
There are vast numbers of divergent rice germplasms in Sri Lanka. As the
development of salinity tolerant cultivars has become a prioritized research
area, it is necessary to assess these varieties and utilize them in breeding
programs. Previously a major salinity tolerant QTL called Saltol 1 has been
discovered in chromosome 1 of Pokkali derived germplams. Assessment of
SSR markers at the region of Saltol 1 QTL and phenotypic assessment of
seedling stage of rice germplasms would give some insight into the
understanding of salt tolerance. In this regard, we analyzed twenty rice
germplasms, including traditional and improved varieties, with five SSR
markers closely linked to Saltol 1. Also morphological traits of the seedlings
were assessed under saline condition which was created with 100mM NaCl
concentration (12 ds/m) in hydroponics. Results showed that root length,
shoot length, fresh root weight, and dry root weight were significantly
different among varieties. Survival index and visual injuries were exhibited
that some traditional varieties and exotic varieties are extremely tolerant
even than Pokkali, the well-known salt tolerant check variety. The
dendrogram obtained from cluster analysis of DNA markers indicated that
some of the tolerant varieties were grouped in separate clusters. Polymorphic
banding patterns of SSR markers obtained from tolerant and susceptible
varieties near Saltol 1 would be useful in selecting parental lines for the rice
improvement breeding programs designed for salt tolerance.
