Drought Tolerance and Evaluation of Genetic Changes in Rice Mutant Lines

Abstract

The genetic improvement of rice through mutation induction to obtain drought resistance is essential for stable and adequate rice production would enable us to anticipate the rice yield-reducing effects of global warming. The aim of this research was to evaluate the rice mutant lines showing tolerance to drought condition and their genetic relationship using SSR markers. Mutant lines were obtained by irradiation of Mira-1 rice variety at primordial state by 25 and 50 Gy doses. Twenty numbers of M4 rice mutant lines, cv. Mira-1 as wild type, cv. Gajah mungkur as positive control and cv. IR64 as negative control were chosen in this study were planted in PVC cylinders in the green house. The result showed that the agronomic trait of rice mutant lines were better than their wild type. Root length of 17 number of mutant lines are longer than their wild type and Gajah mungkur, the longest root obtain was 71.5 cm on 7J4 rice mutant line compared to Mira-1 only which was 25 cm. The number of lateral roots and seeds content per panicle higher than their wild type and positive control. Based on SSR marker linked to root depth, DRO1 showed that 12 numbers of mutant lines polymorphic and changing of genetic of mutant lines which was indicating the mutant lines were tolerant to drought compared to their wild type. The molecular information of rice mutant lines is essential for further development of a new superior variety of rice, which would be an improvement of the variety already existed.

A systematic review on physical mutagens in rice breeding in Southeast Asia

“…Abiotic stress is defined as the detrimental effect of non-living factors on plants in a specific environment including drought, floods, salinity, extreme temperature, heavy metals, and other natural causes. Herwibawa, Sakhidin & Dwi Haryanto (2019) , Amsal & Ishak-Ishak (2018) , Yunita et al (2020) , Meesook, Pongtongkam & Poeaim (2018) , Che Mohd Zain et al (2016) , and Kadhimi et al (2016a) , for example, have conducted research to identify drought-resistant rice cultivars. Researchers from Malaysia, Che Mohd Zain et al (2016) and Kadhimi et al (2016b) exposed rice seeds (MRQ74 and MR269) to 350 Gy of gamma rays and generated osmotic stress using a varied concentration of Polyethylene glycol (PEG) 6,000 ranging from 0–20%.…”

“…Under the drought stress level of −0.03 MPa, the genetic variants in the M1 generation show diversity, and the best combination of mutagen and cultivar is Inpago Unsoed 1, which was irradiated with gamma-ray 100 Gy and then soaked in SA for 2 h ( Herwibawa, Sakhidin & Dwi Haryanto, 2019 ). Amsal & Ishak-Ishak (2018) exposed the Mira-1 rice variety to 25 and 50 Gy of gamma rays and tested with 20% PEG resulting in two (2) from 20 mutant lines; 28H1 and 30F1 mutant lines showing the best characteristics (number of productive tillers; 12 each, lateral root; 142 and 100, and grain yield per panicle; 80 and 124, respectively) for drought tolerant. Lateral roots can develop on any primary root, including crown roots and embryonic, and are used as a drought tolerance indicator.…”

Growth and Yield of Black Rice M4 Induced by Gamma-Rays 200 Gy Under Drought Stress

“…The number of productive tillers affects grain yield. Productive tillers will produce panicles, so the more productive tillers, the higher the number of panicles obtained [20]. Drought stress significantly affected the number of productive tillers of M4 Boyolali variety (Table 3).…”

The potential of Central Java local black rice and red rice as drought tolerant cultivars

“…The root system size affects the absorption of water and minerals from the soil and is related to the size of the plant part above the soil surface [25]. The statistical tests showed that rice cultivars significantly affected the shoot-root ratio.…”