Abstract. Sarwendah M, Lubis I, Junaedi A, Purwoko BS, Sopandie D, Dewi AK. 2022. Application of selection index for rice mutant screening under a drought stress condition imposed at reproductive growth phase. Biodiversitas 23: 5446-5452. Drought is a condition of limited availability of water that can reduce rice growth and productivity, and may threaten food security. Therefore, efforts are needed to produce drought-tolerant rice genotypes. This study aimed to select drought tolerant of the M3 mutant upland rice population at the reproductive growth phase. This research was carried out in dryland at BATAN, Indonesia, from September 2020 to February 2021, using an augmented design. The study employed 360 ??genotypes of mutant upland rice and 5 check varieties, namely Salumpikit, IR20, IR64, Limboto, and Situgintung. The selection index was constructed based on multivariate analyses such as correlation, path, and Principal Component Analysis (PCA). The coefficient of the selected main component can be used as a selection index. Before selecting the character values of each genotype, the values were standardized to obtain the same degree of value. The results showed that grain weight per hill (W.G.), panicle density (P.D.), panicle length (P.L.), and the number of filled grains per panicle (NFG) could be used as selection criteria for mutant upland rice tolerant to drought at reproductive growth phase. The selection index formula was I = (5*0.44*WG) + (2*0.41*PD) + (0.23*PL) + (0.42*NFG). Selection of genotypes of mutant upland rice based on weighted index selection resulted in 89 genotypes with high yields and good agronomic characteristics so that they could be tested in further research.

Developing new high-yielding rice varieties resistant to bacterial leaf blight (BLB) is an effective strategy for controlling BLB. Several advanced doubled haploid rice lines derived from anther culture previously selected need assessment for BLB resistance. This study aimed to evaluate the resistance of these lines to BLB pathotypes III, IV, and VIII in the vegetative and generative phases. The experiment took place in a greenhouse using 16 rice genotypes comprising 12 doubled haploid rice lines, two commercial check varieties (Inpari 18 and Inpari 34), and a BLB-resistant and susceptible check variety (Code and TN-1, respectively). Inoculation began with the leaf clipping method using a suspension of the pathogen Xanthomonas oryzae pv. oryzae (Xoo) at a concentration of 109 cfu/ml. The results indicated significant influences on disease severity and intensity of BLB of pathotype, genotype, and the interactions between pathotype and genotype, finding their values higher in the vegetative phase. Six doubled haploid lines ranged from resistant to moderately resistant (disease severity 2.0%–10.7%, disease intensity 6.7%–36.8%) to pathotypes III and IV in two growth phases, i.e., HS1-35-1-4, HS4-15-1-9, HS4-15-1-16, HS4-15-1-24, HS4-15-1-26, and HS4-15-1-28. All those doubled haploid lines were susceptible to BLB pathotype VIII in the vegetative phase and moderately susceptible in the generative phase.

Abstract. Nurhidayah S, Purwoko BS, Dewi IS, Suwarno WB, Lubis I. 2023. Agronomic performance and selection of green super rice doubled haploid lines from anther culture. Biodiversitas 24: 819-826. Rice is the staple food of most Asian, including Indonesian people. Plant breeding plays an important role in producing high-yielding varieties of rice to meet national carbohydrate sufficiency. Green Super Rice (GSR) is an alternative for rice variety development that has the advantages of high yield, good quality, pest resistance, and efficient fertilizer use to support sustainable agriculture. This study aimed to evaluate the agronomic character of GSR doubled haploid (DH) lines derived from anther culture and determine the best GSR rice lines based on index selection. The treatment was 65 genotypes consisting of 60 DH of GSR lines from anther culture of 5 combinations of crosses and 5 check varieties. The study used a randomized complete block design with three replications. The results showed that most of the tested lines had similar agronomic performances to the check variety Inpari 42 Agritan GSR. Almost all agronomic characters of the GSR DH lines had high genetic variability. Most characters had a high category of broad-sense heritability except panicle length. Line selection using index selection for economically important agronomic characters yielded 27 GSR DH lines having high productivity, number of productive tillers per hill, number of total grains per panicle, and percentage of filled grains per panicle.