Studies on the genetic parameters of quantity traits in upland rice
Seven traits of 57 upland rice varieties were studied on broad-sense hereditability, genetic correlation, genetic advance and selection index. The results showed that the broad-sense hereditability of plant height, length-breadth ratio of flag leaf, grains per plant, main spike length and 1 000-grain weight was high. The range of hereditary change of grains per plant, grain weight and effective spikes per plant were higher as compared to other traits. These 3 traits had huge genetic potential for breeding by selection. The 1 000-grain weight and grains per plant had significant genetic potential and advance to improve grain yield. Grains per plant in the population had a dominant genetic advance in the following generations. The 4 traits, i.e. grain weight per plant, grains per plant, 1000-grain weight and effective spikes, were used as selection indexes for combined selection, and the relative selection efficiency was upto 219.34 %, 119.34 % higher than the direct selection with grain weight per plant.