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Abstract. Akbar MR, Purwoko BS, Dewi IS, Suwarno WB, Sugiyanta. 2019. Short Communication: Selection of doubled haploid lines of rainfed lowland rice in preliminary yield trial. Biodiversitas 20: 2796-2801. Yield trial is an important step in rice breeding program. This research was aimed at evaluating agronomic characters and selecting the best doubled haploid rainfed rice lines for next advanced yield trial. An experiment was conducted in Indramayu from March to August 2017. The research was arranged in randomized complete block design (RCBD) with three replications. Materials used were fifty-eight doubled haploid lines and two check varieties namely Ciherang and Inpari 18. The results revealed that all observed characters had broad genetic variability and high heritability. The number of productive tillers and the number of filled grains per panicle had a positive correlation and direct effect on productivity. Based on index selection, thirty lines were selected to have good agronomic characters and high yield. These lines had characteristics of plant height (85.7-124.7 cm), number of productive tillers (8.6-14.8 tillers), day to harvest (104.0-117.3 days), number of filled grains per panicle (136.7-264.7 grains), number of total grains per panicle (152.0-305.7 grains), weight of 1000 grain (21.5-31.3 g), and productivity (4.1-6.8 tons ha-1). Keywords: good agronomic trait, high yield potential, selection index

Abstract. Akbar MR, Purwoko BS, Dewi IS, Suwarno WB, Sugiyanta, Anshori MF. 2021. Agronomic and yield selection of doubled haploid lines of rainfed lowland rice in advanced yield trials. Biodiversitas 22: 3006-3012. Selection process is important step to obtain high yielding variety. This study aimed to obtain information on agronomic performance of doubled haploid lines of rainfed rice in advanced yield trials and select the best lines for multi-location yield trials. Two experiments were conducted in Bogor and Subang using a randomized complete block design for each location and consisted of 35 doubled haploid lines and two check varieties namely Ciherang and Inpari 18 as a treatment. The result revealed that interaction between genotype and environment (G x E) significantly affected all agronomic characters, except on the panicle length. Characters with high heritability value were all agronomic characters except number of productive tillers and productivity. Genotypic correlation analysis showed that number of productive tillers and weight of 1000 grains had significant and positive correlation with productivity. The selection used weighted selection index based on multivariate analysis. Fourteen lines were selected for multi-location yield trials. These lines had characteristics as follows: number of productive tillers (14.0-17.7 tillers), weight of 1000 grains (24.7-32.5 g), and productivity (5.0-6.2 ton ha-1). The selected lines can be evaluated further to obtain superior lines in multi-location trials.

Developing of drought tolerant hybrid rice varieties requires parental lines which have tolerance to drought. Polyethylene glycol (PEG) has been widely used as an osmotic solution for detecting drought 58025B, GMJ 14B, IR 80154B, GMJ 15B, R 3, PK 90, dan PK 12. Kata kunci: PEG, perkecambahan, tetua padi hibrida, toleran kekeringan PENDAHULUANKekeringan merupakan salah satu cekaman abiotik yang dapat menyebabkan penurunan hasil dan kualitas gabah padi (Pandey dan Bhandari, 2008). Kehilangan hasil disebabkan oleh cekaman kekeringan diperkirakan mencapai 58% (Ouk et al., 2006). Oleh karena itu, menjadi tantangan bagi pemulia untuk merakit varietas padi toleran cekaman kekeringan sekaligus memiliki potensi hasil tinggi.Teknologi padi hibrida merupakan alternatif untuk mencapai potensi hasil tinggi pada kondisi optimum

<abstract> <p>The development of tolerant rice varieties using doubled-haploid technology is necessary to speed up the release of a variety tolerant to salinity stress. However, this requires a reliable screening method and selection index model for enhancing selection effectiveness. One approach is through the development of a selection index based on factor analysis under soil salinity screening in the greenhouse. The objective of this study was to develop a selection index model based on factor analysis and select tolerant doubled-haploid lines under high salinity conditions. The experimental design used was a split-plot design with salinity stress treatments as the main plot, i.e., normal (0 mM NaCl) and saline (25 mM NaCl ~ 5.6–5.8 dS/m) and 42 genotypes as the subplot. The genotypes consisted of 36 doubled-haploid lines, four commercial varieties, and two check varieties. The results indicated that a salinity selection index model involving yield and productive tiller traits could be used for selecting rice genotypes tolerant to salinity stress in soil artificial screening. This index which was developed through a combination of factor analysis, stress tolerance index (STI), and path analyses have identified 15 doubled haploid rice lines which were considered as good tolerant lines under salinity stress in soil artificial screening.</p> </abstract>

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Begomovirus infection has a significant impact of lowering chilli yield in Indonesia. A constraint of narrow genetic variability of chilli in Indonesia has made the mutation breeding program as a solution worth-pursuing in increasing the genetic variability. The objective of this study was to determine the LD50 point for each of the five irradiated chilli genotypes and the optimum dose of gamma irradiation in inducing chilli resistance to Begomovirus and other improved agronomical traits. The study was conducted in the Indonesian Vegetable Research Institute (IVEGRI) at CikoleLembang, elevation 1,200 m above sea level, from March to December 2013. Split plot design was used with genotype as main factor (Kencana, Lembang-1, SSP, Tanjung 2, Seloka) and irradiation dosage as sub-factor (0, 200, 400, 600, 800 Gy). All treatments were replicated three times. The results showed that LD50 points of the five irradiated chilli genotypes were in the range of 422.64-629.68 Gy. There were some chilli genotypes in the population of M2 that had high coefficient variance genetic (CVG) and broad sense heritability (h 2 bs) value for disease incubation time. This could be used as resistance parameter to Begomovirus and improvement parameter of several agronomical traits.

Salinity is one of the most serious problems in rice cultivation. Salinity drastically reduced plant growth and yield, especially at seedling stage. Several rice genotypes have been produced, but their tolerance to salinity has not yet been evaluated. The study aimed to evaluate salinity tolerance of rice genotypes at seedling stage. The glasshouse experiment was conducted at Cimanggu Experimental Station, Bogor, from April to May 2013. Thirteen rice genotypes and two check varieties, namely Pokkali (salt tolerant) and IR29 (salt sensitive) were tested at seedling stage. The experiment was arranged in a randomized complete block design with three replications and two factors, namely the levels of NaCl (0 and 120 mM) and 13 genotypes of rice. Rice seedlings were grown in the nutrient culture (hydroponic) supplemented with NaCl at different levels. The growth and salinity injury levels of the genotypes were recorded periodically. The results showed that salinity level of 120 mM NaCl reduced seedling growth of all rice genotypes, but the tolerant ones were survived after 14 days or until the sensitive check variety died. Based on the visual injury symptoms on the leaves, five genotypes, i.e. Dendang, Inpara 5, Inpari 29, IR77674-3B-8-2-2-14-4-AJY2, and IR81493-BBB-6-B-2-1-2 were tolerant to 120 mM salinity level, while Inpara 4 was comparable to salt sensitive IR29. Hence, Inpara 4 could be used as a salinity sensitive genotype for future research of testing tolerant variety. Further evaluation is needed to confirm their salinity tolerance under field conditions.