Growth phase-base agro-morphological characterization of pigmented rice accessions in PhilRice genebank

Vast rice accessions serve as source of genes to widen rice genepool. In order to assess levels of diversity, currently, 58 traits are being used as descriptor to obtain fundamental data needed for identification of promising accessions for breeding. This include descriptors for both qualitative and quantitative data from all growth stages, however, the use of these traits is time consuming. Thus, this study was designed to assess the genetic diversity using only 39 qualitative agro-morphological characters to shorten the time for data generation. This was done at three different growth phases of a rice plant namely vegetative, reproductive and post-harvest stages using 260 pigmented rice accessions. Results showed the presence if ligule and ligule shaped showed no variation among test genotypes. All 260 genotypes produced two-cleft types. Absence of anthocyanin coloration was observed in most of the rice germplasm tested. Light green to dark green was the color observed in the basal leaf sheath, auricle, collar and leaf blade while wide range of color variability was observed in lemma/palea and including that of apiculus. Cluster analysis using UPGMA revealed that overall similarity observed using all the 39 qualitative characters was 57% with 37 cluster at 0.64 similarity coefficient. However, different level of diversity was observed among the three-growth phases. Vegetative stage showed 57% diversity, reproductive stage gave 64% and post-harvest had the highest level of diversity amounting to 74%. This result showed that the level of diversity score of pigmented rice germplasm varies from rice development stage. This signifies that these germplasm may possess exclusive variability and unique features that can be used to help identify and develop germplasm that may be useful in rice varietal improvement.