Drought Resistance Analysis of the North Sulawesi Local Rice Based on the Root Characters Nio Song Ai, Ludong Daniel Peter Mantilen

Rice is one of the important staple foods in Indonesia with carbohydrate as its major component. Rice germplasm is so diverse in Indonesia including in North Sulawesi Province, which has 4 local rice cultivars, i.e Superwin, Ombong, Temo and Burungan. Regarding with the food security program in this province as well as in Indonesia, a study was conducted to evaluate root characters (the number of adventitious roots, maximum root length, root dry mass, root:shoot ratio, the number of hardpan penetrated roots) as response to drought in these North-Sulawesi local rice cultivars grown in the soil mixture at the vegetative phase. The drought treatment consisted of three different intensities (watering until 100% field capacity/DA, watering until 50% field capacity/½TA and no watering/TA) for 2 weeks in the glasshouse experiment using polyvinyl chloride (PVC) pots with 125 mm height and 60 mm diameter. In general, the drought treatment decreased the number of adventitious roots, root dry mass, and root:shoot ratio The roots of Temo and Burungan were able to penetrate the hardpan (mixture of paraffin and vaseline that was equal to 12 bar hardness) under drought, but the capacities were low. Based on the root characters, Temo and Burungan had higher drought resistance than the other cultivars. The results of this research enriched the information of drought resistant rice selection that was easy, cheap and fast in the plant breeding program in North Sulawesi