Agro-morphological characters of mestizo 1 (PSB Rc 72H) from different seed sources

The national hybrid rice commercialization program was launched in January 1998. The first hybrid extensively produced and promoted under this program was Mestizo 1. officially released as PSB Rc72H. This hybrid was released in 1997 and bred by International Rice Research Institute (IRRI). Upon its release, parental lines were given to PhilRice for multiplication and maintenance. Since then, hybrid parentals are continuously reproduced by researchers and seed growers to produce the hybrid. Hence, periodic checking of the hybrid is necessary to assure farmers that they are getting pure and true hybrid seeds. Twenty nine different seed sources of Mestizo 1 hybrids produced last dry season of 2003 by PhilRice, different seed growers and cooperatives and SL Agritech were compared morphologically to Mestizo 1 produced by IRRI. Experiment was laid-out in randomized complete block design with four replications and plot size of 6 sq m. Agro-morphological data were collected at different growth stages. Purity of the samples was also assessed. Analysis of variance showed no significant differences among entries in terms of leaf length and width, culm length, tiller number, panicle length, grain length and width, 1000-grain weight, number of spikelets per panicle, and grain yield. Qualitative traits like colors of blade, basal leafsheath, collar, ligule, auricle, apicules, seed coat, and sterile lemma; leaf angle, blade and lemma-palea pubescence; leaf angle; panicle and endosperm types, secondary branching and grain scent of all the test entries were exactly the same with Mestizo 1 produced by IRRI. Differences observed in terms of panicle exsertion, stigma and node colors, awning, spikelet fertility and flagleaf angle could be attributed to off-types present in plants sampled. Generally, results showed that Mestizo 1 test samples were identical to the hybrid produced by its breeding institution. Purity evaluation of the different entries showed that IR58025A was the most common mixture in the samples indicating the presence of IR58025B during AXR F1 seed production. Other off-types were IR58025B and some inbreds.