Keefektifan Cepat Uji Ruang Gelap untuk Seleksi Ketenggangan terhadap Naungan pada Padi Gogo

Abstract

Several low-light intensity (LI) tolerant and LI-sensitive genotypes of upland rice were subjected to dark condition. To determine the &~ciency of respiration, starch, and carbohydrate were analyzed from the leaves and stems of seedlings grown in dark condition for three days. In the second experiment, 200 accessions of upland rice were exposed to dark condition for nine days and the survival of seedlings were measured for determining the tolerance to dark condition. The selected darktolerant genotypes were compared with the LI-tolerant genotypes derived from previous experiment using paranet and field test. The effectivity of this method was judged from the number of genotypes that are consistently tolerant under the three conditions. All the LI-tolerant genotypes were highly tolerant, and all the LI-sensitive genotypes were sensitive to dark condition. Exposing seedlings to dark condition for three days resulted in the decrease of starch and carbohydrates, the decrease of which was much lower in LI-tolerant genotypes, indicating a more efficient respiration. From the evaluation of 200 accessions, dark-condition quick test was able to select 14 of 15 selected LI-tolerant genotypes determined under paranet test. Thus, this quick test is a reliable method to be used for screening shading tolerance in upland rice.