Adaptasi Dan Stabilitas Hasil Galur-galur Aromatik Padi Sawah Di Sumatera Utara

This research was aimed to describe the yield stability and growth adaptation of elite lines of aromatic rice in rice production centers of North Sumatra. The experiments were conducted at 10 sites during dry season (DS) 2001 and DS 2002. Research materials consisted of 12 elite lines introduced from IRRI with IR64 as check variety. The treatments were arranged in a randomized block design (RBD) with three replications. Stability analysis was performed using methods of Eberhart and Russell, Finlay and Wilkinson, and Francis and Kanennberg. The results showed that the interaction of genotype x environment effect was very significant, indicating the presence of specific line adaptation on a particular environment. Genotypes which had the highest average yield were not always stable genotypes, as was shown by IR71137-49-1-2 which was more suitable to the sub-optimum environment. Lines IR71143-223-3-2-2-3, IR71146-97-1-2-1-3, IR65610-24-3-6-3-2-3, IR66696-49-1-2, IR71146-407-2-1-2-1, IR71146-122-1-1-2-1 were considered as stable genotypes according to the three analysis methods and each line showed high average yield. Those genotypes are suggested to be planted in the high productivity environments in order to obtain its optimum genetic expressivity on grain yiel

Initial Study of the Response of Ultra Early Maturing Rice Genotypes to Drought Stress Conditions in Vegetative and Generative Phase

Global climate change has caused the spread of drought prone areas. Drought stress for rice mostly happen in upland, rainfed, and limited irrigation lowland areas. Development of varieties suitable for those areas would significantly increase rice yield. Early maturing genotypes are useful to anticipate predictable early or terminal drought by escape mechanism. Nevertheless, unpredictable drought happening during early, mid season and final planting season results in the need of genuinely droughttolerant genotypes. Combining early maturing and drought tolerant seems to be highly powerful to anticipate drought. This research was aimed to study the response of 23 early maturing rice genotypes consisting of 3 released varieties, 10 local varieties, and 10 introduced lines. The genotypes were exposed to vegetative (watered until 7 days after transplanting and rewater when the susceptible check was drying) and generative phase (watered until 28 days after transplanting and rewatered only if susceptible check was drying), drought stress conditions, and also optimum condition. The experiment was conducted in ICRR Experimental Station in Sukamandi during Dry Season (DS) of 2009. The genotypes were treated with three watering conditions mentioned above without replication to initially see the descriptive statistics of some agronomic traits of the genotypes under the mentioned conditions. The results showed that based on yield, Drought Sensitifity Index (DSS), Relative Values (RV), and agronomic performance, OM 1490 had been identified as tolerant to vegetative and generative drought stresses. It yielded 28.17 g/plant, 24.11 g/plant, and 24.72 g/plant at optimum, vegetative, and generative drought condition, respectively. OM 1490 had been released as Inpari 13 in 2010 and it had beed utilized for further breeding effort resulting new promising lines