Screening and Identification of Upland Rice Lines Derived Recurrent Selection for Drought Tolerance

Abstract

Variety assemblings for higher yield capacity of upland rice which tolerant to drought stress and highly adaptable to climate change has been needed to support the effort to increase both rice yield and the upland rice field extensification. This research aims to screen and identify an agronomic character of upland rice lines as the result of recurrent selection to a seedling stage on the drought stress. Materials were 180 rice lines as the result of recurrent selections from two local varieties Sriwijaya and Bugis with other two drought tolerant lines IR7858-1 and N148+. Twenty seeds each genotype were seeding in seed pods adjusted with stripe check such Situbagendit and Inpari 6 as tolerant and susceptible lines respectively. Drought stress treatment had conducted in a week, began at two weeks seedling age with a scoring value 0-9 (SES IRRI), at the same time were taken sample soil to measure the soil water content was done at a depth of 20 cm. Then, the crops were watered again to observe the recovery capacity of the crops, with the scoring 1-9 (SES IRRI). Anatomically stomatal proximation was observed for both susceptible and tolerant rice lines. The selected lines would transplant in the field to record the yield capacity and other agronomic characters. The SES screening resulted in 53 tolerant lines, 99 moderate tolerant, and 28 susceptible to the drought stress which had the soil water content ranged from 11.9 to 12.7 percent. Anatomic stomatal observation showed that the stomatal structure and density of susceptible lines were closer and more than tolerant lines. The highest percentage of filled grains showed by the intercross line Sriwijaya/IR7858-1 about 77.4 to 85.1 percent with averagely 80.7 percent, which was a high category with the scale of 3 SES IRRI. The selected drought stress lines with better agronomic character would continuously test to know the yield capacity in the environmentally specific location.

Genetic Diversity and Agromorphological Characteristics of 50 Upland Rice Genotypes Derived from Recurrent Selection

“…The highest length of panicle derived from Sriwijaya/N-148 elders, namely 25 cm -34.34 cm. The panicle length observed was better compared to the results of the study Herawati et al (2017b) which produces panicles in the F3 generation from Bugis/IR-7858-1 and Sriwijaya/IR-7858-1 elders on average 22.4 cm and 21.9 cm.…”

“…The highest average number of tillers derived from Sriwijaya/N-148 crosses, which is 14.08 and the lowest number of tillers is from Bugis/N-148 crosses, 10.50 (Table 2). Variable productive tillers also showed better growth compared to previous studies conducted by Herawati et al (2017b) in the F3 generation which produces the highest productive is 9.3 tillers.…”

“…Plant height in all genotypes varies greatly, the highest plant height is found in Bugis /N-148 crosses, 166.5 cm, but the highest average is from Bugis/IR-7858-1 crossing, which is 151.58 cm and the lowest range comes from of the Sriwijaya/N-148 crossing population of 105 cm with an average of 127.83 cm (Table 2). Plant height observed to have genetic progress, when viewed in the study Herawati et al (2017b) had an average plant height of 139.5 for elders from Bugis/IR-7858-1 and 109.7 for elders of Sriwijaya/IR-7858 -1. According to IRRI (2013), the height of lowland rice is divided into 3 categories, namely low: if the plant height is below 110 cm, medium: if plant height ranges from 110 cm -130 cm, and high: if the height of rice plants is more than 130 cm.…”

“…Each genotype is planted in one row consisting of 20 populations so that ± 3000 plants are obtained. The materials used were 50 rice genotypes resulting from a recurrent selection from Bugis x N-148 crosses, Bugis x IR-7858-1, Sriwijaya x N-148, and Sriwijaya x IR-7858-1 (Herawati et al, 2017b ) and NPK fertilizer. The materials used in this research are nails, hammers, bamboo, waring, meters, ropes, nets, hoes, scales, laptops, plastic envelopes/bags.…”

Spatiotemporal Variability in Soil Water Content Profiles under Young and Mature Oil Palm Plantations in North Bengkulu Regency

“…Similarly, watershed integration rather than separate watersheds was more accurate in predicting potential drought distribution and improving water supply needs as a part of irrigation practices [31]. Agronomists and planters can also use the drought distribution information to develop drought-tolerant varieties to sustain crop productivity in such a region during the dry season [32]. Overall, this study offered a wide range of practical applications to develop a precise agriculture system, particularly concerning soil water.…”