Tolerance of F6 Red Rice Lines against Iron (Fe) Stress

Dryland area in Indonesia reaches 108.8 millions ha (69.4%) of the total dry land with the potential to expand the area of food crops reaching 7.1 million ha, which is dominated by ultisol and oxisol soil types. Plant constraint cultivation on ultisol soil types is the acidic soil pH with high Al and Fe levels. One of the efforts that can be made to cultivate plants on ultisol soil is the selection of plants that are tolerant of Fe stress. This study aimed to determine a tolerance level and F6 red rice lines that were tolerant of iron (Fe) stress in ultisol soils. The experimental design used was factorial Completely Randomized Design (CRD) consisting of 2 factors, the first factor consisted of 12 treatments (10 test lines and 2 comparison varieties) and the second factor  was iron stress with concentrations (0 ppm and 551,55 ppm). The stress was applied after 3 WAP. The stress resistance test to iron (Fe) should that all lines of red rice F6 on ultisol soils have a score of 1 which indicates the stress tolerance of Fe at a concentration of 551,55 ppm Fe. The 23A-56-30-25-12 and 23A-56-30-25-13 lines were the best lines that were tolerant of 551,55 ppm iron (Fe) stress with the highest growth and yield. The lines tested can be developed on ultisol soils because they are tolerant of Fe

The improvement of early maturity red rice mutant trait for drought tolerance

Accession of red rice does not have the traits of early maturity, drought tolerance and high yield. Mutation is needed to obtain the desired genetic resources. Gamma-ray irradiation is the right method because it was proved capable of producing hundreds of new varieties, which are better than the previous. This study aimed to identify the improvement of early maturity and drought tolerance of red rice mutant to gamma ray irradiation results. The research materials are M4, M5 and M6 strain, which are derived from the Bangka’s accession local red rice (Celak Madu, Ruten Puren and radix). The three accession seed have been treated with gamma-ray irradiation doses of 150, 200 and 250 Gray. The results showed gamma ray irradiation dose of 150 Gray and 200 Gray to red rice accession can form a mutant with the character of harvesting time less than 115 days after planting and was more drought tolerant than the previous. M6-GR150- 1-9-13 strain was selected as a candidate for early maturity, drought tolerant and high yield mutant

Selection Strategy of Drought Tolerance of Red Rice Mutant Lines

Most of Indonesian red rice is not grown in dry land. New varieties could be breeded through mutation breeding. This research objective was to evaluate the selection strategy of drought tolerant on red rice. The study was conducted on ultisol soil in Bangka Belitung Province, Indonesia, in February 2012-February 2015. It consisted of three activities, selection M5, evaluation of selected M5 and evaluation of drought critical period on selected M6. Mutant of M5 was selected and evaluated with polyethylene glycol (PEG) -0.5 MPa and less of soil moisture. Selected M6 was evaluated to observe a critical period of drought stress. Evaluation with PEG produces five superior mutants that more vigor than the elders. Selection on low humidity shows that M5-GR150-1-9 produces higher filled grain and weight filled grain than other mutants and elders. The selected red rice line M5-GR150-1-9-13, has a better tolerance towards drought than its control. It could be obtained such mutant lines which have a high yield, early maturing and drought tolerant from the result of six generations gamma irradiation mutant selection