Response of new promising rice (Oryza sativa L.) lines and varieties for processing in South Central Coastal Vietnam

Genetic performance, heritability, and correlation of traits in new plant type of rice lines for highland ecosystem

Abstract. Maruapey A, Wicaksana N, Karuniawan A, Utami DW, Windarsih G. 2020. Swampy rice lines performance for iron toxicity tolerance and yield components under inland swamp at Sorong, West Papua, Indonesia. Biodiversitas 21: 5394-5402. The extensification of sub-optimal lowland farming strategy is expected to support the increase of rice production. Based on the efforts, the development of tolerant rice varieties to Fe-toxicity to be used in the swampy land area is one of the approaches for increasing rice production. Currently, promising rice lines that are tolerant to Fe-toxicity has been developed using molecular breeding approach for inland swampy area. The objective of this research was to evaluate the performance of 15 promising rice lines that have various genetic backgrounds in inland swamp in Sorong, West Papua. The field experiment was conducted during the second rice planting season (August 2018 to February 2019) to evaluate the performance of the promising rice lines to the morpho-agronomic performance under the lowland swamp conditions. The trial was laid out in a Randomized Complete Block Design (RCBD) consisting of 4 m x 5 m square plots, with 25 cm x 25 cm planting distance and 3 replications. The results revealed that most of the lines had good performances on the Fe-toxicity tolerance, based on bronzing, root length, and biomass characters. The G1 line had the best performance on yield component characters, especially the panicle length. This line also had the highest grain yield (6.15 ton.ha-1) followed by the next promising line of G7 (5.92 ton.ha-1). The genetic performance of these lines showed that they contained IRT (Iron Regulation Transporter) alleles that contributed to partitioning the Fe tolerance mechanism.

The main purpose of plant breeding programs is to improve varieties acceptable to rural communities. Participatory crop improvement for rice lines was initiated using techniques which were designed with the purposes to strengthen the collaboration between breeders and stakeholder especially farmers to produce varieties. Before the promising rice lines released and adopted by farmers, it is necessary to study the preferences on characteristics, especially its quality, because farmers have their own criteria or considerations before adopting a new variety. A bottom-up preferences in this study is to understand the major phenotypic performance, sensory quality, and provide recommendations for improving promising rice lines (Oryza sativa L.). The respondents are farmers, extension workers, members of academic institutions, and local government officers, came from four Regencies (Banyumas, Magelang, Batang, Klaten) that representing the main rice production areas in Central Java province. The attribute data on rice characteristics showed that grain size, plant age, and lemma shape of apiculus was essentially regarded as a major factor for better performing varieties. The respondents’ preference provides recommendations for breeders to release promising rice lines GM 8 and GM 2 into commercial varieties.

Developing and cultivating new promising rice lines with high yield potential and blast disease resistance is an important goal of rice breeding. The study was to evaluate some developed new elite rice lines for high yield, blast resistance, effective resistance genes to Pyricularia grisea and rice stem borer insect as well as assessment of the genetic diversity in these lines using microsatellite markers. Significant differences were found among the studied new promising lines and their parents for yield and its component traits. Promising lines; GZ11190-3-13-1-1 and GZ11190-3-13-4-1 gave the highest grain yield compared with their parents; Giza 178 and GZ6296-12-1-2-1-1 and superiority for all studied traits. Also under this study, twenty six isolates were identified as five main groups i.e., IC, ID, IF, IG and IH, but ID and IH groups were considered the most common race, Pib resistance gene was the most effective gene to blast fungus. Promising lines GZ11190-3-13-1-1 and GZ11190-3-13-4-1 proved resistance for all tested isolates under greenhouse condition and moderately resistant for stem borer insect. For genetic diversity analysis, twenty SSR markers were polymorphic amplifying a total of 102 alleles. Characterization of these markers showed high discriminating power with an average polymorphism information content (PIC) of 0.754.Major allele frequency ranged from 0.475 (RM590) to 0.923 (RM5 and RM5313), with an average of 0.705. The cluster analysis based on microsatellite SSR markers grouped 13 rice genotypes into clear separate groups and was able to reveal close genetic relationships between rice genotypes used in rice breeding program.

Rice is an important food crop in Vietnam and facing challenges due to climate change, limited cultivation area, and limited adaptable varieties. Therefore, field experiments were carried out in two seasons of summer 2022 and spring 2023 at the Agricultural Science Institute for Southern Coastal Central of Vietnam (ASISOV), Binh Dinh province, to evaluate the growth, development and yield of new promising short duration rice lines and varieties in Binh Dinh province. Promising 10 lines and varieties namely ANS1 (control), BDR97, BDR57, BDR79, BDR87, BDR36, Line 159, Line 243, Line 64, and Line 46 were used for the study. They were arranged in a randomized block design with three replications. Research results showed that the duration of rice lines and varieties ranged from 90 to 112 days. The yield of the lines and varieties was from 5.94 to 7.44 t/ha in the summer season 2022 and 6.42 to 8.05 t/ha in the spring season 2023. The quality of rice lines and varieties was rated from average to good. Two new promising varieties were identified, including BDR79 and BDR57, with a short duration of 91-103 days, yield from 7.27-8.05 t/ha, higher than the control variety from 11.6-20.5% and belonging to good quality classification.

Rice is one of the world’s oldest important crops. Qualitative traits can be useful for the identification of promising rice lines. In this study, seventeen advance rice lines were evaluated for qualitative traits. This assessment was carried out to analyse the variability in genotypes, based on 49 important qualitative traits of rice. Data on morphological parameters was collected from each line at suitable phase of growth to check variation. Findings were recorded according to descriptors for rice. Dendrogram was constructed which divided all the genotypes into seventeen major clusters, each subdivided into smaller sub-clusters. The pattern of cluster based on qualitative traits revealed the wide genetic variation. A high level of genetic variability based on qualitative traits was observed in this study. The genetic improvement of the rice needs the availability of genetic variability in promising lines. Significant phenotypic information and these variability has potential to develop quality rice for future breeding programs.

Improvement of nutrient-use efficiency (NUE) in rice is important for increasing productivity. Rice varieties with tolerance to phosphorus (P) deficiency increase the productivity in P-deficient fields. Therefore, the objective of this study was to develop high yielding, P-deficiency tolerant rice varieties to enhance the NUE. High yielding and popular rice varieties (Bg300 and Bg94-1) and known P-deficiency tolerant rice varieties (H4 and At353) were used as female and male parents, respectively, in a crossing program. Single seed descent approach was used for rapid generation advancement. Bg300/At353 and Bg94-1/H4 crosses were advanced from F2 to F6 in planthouse condition under minimum fertigation for restricted growth. In F7 generation, 310 recombinant inbred lines (RIL) in both crosses were space-planted and 40 RILs were selected from each cross. Selected RILs were screened in a hydroponic system at 10 μM P level to select the best lines for P-deficiency tolerance. Multiple plant traits were used for selection and the most promising 20 rice lines were selected as the best performers under P-deficient hydroponic conditions. Marker assisted selection was carried out to confirm the presence of PSTOL1 gene. Selected rice lines were evaluated for agronomic traits and yield parameters. Ten promising rice lines were identified as high yielding lines with accepted agronomic traits.

Bacterial leaf blight (BLB) is one of the major and oldest diseases of rice. The best cost effective management of this disease is the development of resistant cultivars. Morphological and molecular screening are widely used approach in the recent scenario for identifying BLB resistant cultivar. In present study, two experiments were carried out to identify the BLB resistant rice lines and varieties. An active strain of Xanthomonas oryzae pv. oryaze (Xoo.) BXO-09 was used for the inoculation experiments. Then, morphological rating was done to find out the resistant rice lines and varieties whereas three RFLP primers (RG136, RG556 and pTA248) were used for identifying the BLB resistant genes. Through morphological analysis, the rice line RC251 was recorded as susceptible where the rest of the rice lines resulted moderately susceptible or moderately resistant. Among the rice varieties, BR-26, BRRI Dhan31, IRBB5, IRBB21, IRBB60, IRBB65, and Kumragur were recorded as resistant where BR-11, Binadhan-8, and Binadhan-10 were found highly susceptible to BLB. In case of RFLP marker based analysis, a specific type of banding pattern was observed for IRBB5 for RG556 primer which indicated the presence of xa5 gene. For RG136 primer 8 kb single band was formed for different lines and varieties whereas only IRBB60 showed 2 fragments of 8 kb and 5 kb which also indicated the presence of xa13 gene. Finally, DNA amplification of 27 rice lines and varieties using pTA248 primer showed the band at 4 kb position for the BLB resistant lines and varieties and 3.7 kb position for the susceptible lines and varieties. The findings of morpho-molecular characterization information could be useful to the breeders for further planning of developing BLB resistant cultivars.

Weather phenomenon and erratic rainfall are some of the symptoms of global climate change. These challenges attempt to increase rice production in tidal swamps or submerge land in the long term. An effort to form tolerant rice varieties to stress in tidal swampland has been carried out through crossing between superior varieties and local rice. This study aims to analyze the results of several promising rice lines and search for the potential rice lines to be released as new tidal swampland varieties. The experiment was carried out in tidal swamp rice area centers, in Karang Agung, South Sumatra, Balandean, South Kalimantan and in Indramayu, West Java Indonesia. Fourteen rice lines and four check varieties namely IR42, IR64, Inpara 8 and Inpara 9 were used. Field experiments used a Randomized Complete Block Design (RCBD) with four replications. Results showed that the environment, genotype, and interaction between environmental genotypes had a significant influence on all characters. The appearances of the lines were superior in Karang Agung and less well on Balandean. The yield was positively correlated with plant height, the number of productive tillers and filled grains per panicle. There were five lines with a high yield equivalent to the best check varieties, namely Inpara 9, IR 102860-8: 66-BB, IR 102860-8: 42-BB, IR 101465-8: 23, IR 101465-5: 25, and B13522E-KA-5-B.

Rice in Indonesia is still the main staple food, and every year the demand has increased. Indonesian governments have policies to reach self-sufficiency. The strategic programs to increase rice production were through breeding programs. The research was conducted on paddy fields in the village of Ranomeeto District of South Konawe. The study was carried out from October 2018 to April 2019. This study aimed to determine the differences in the agronomic traits in the aspect of vegetative and generative character from some new types of advanced red rice promising lines grown on the paddy field. The experiment was laid out based on Randomized Complete Block Design (RCBD), which consisted of six red rice lines (GS12-1, GS12-2, GS44-1, GS44-2, GS16-1, GS16-2) and one check variety (trisakti). Each treatment was repeated four times, so there were 28 experimental units. Parameters observed were plant height, leaf number, leaf area, number of tillers, panicle length, total grain number, 1000-grain weight, filled grain percentage, unfilled grain percentage and dry weight per m2 The results showed that there were differences in the agronomic traits of the promising rice lines GS12-1, GS12-2, GS44-1, GS44-2, GS16-1, GS16-2, and trisakti variety on paddy field. The new type of advanced red rice promising lines can well be adapted on paddy fields obtained in GS16-1 lines, followed GS16-2 lines and GS44-2 lines.

Single nucleotide polymorphisms in GBBSI and SSIIa genes in relation to starch physicochemical properties in selected rice (Oryza sativa L.) varieties

Glutinous rice (Oryza sativa), despite its unique culinary qualities, typically yields less than other rice varieties, posing agricultural and economic challenges. The construction of a glutinous thermo-sensitive genic male sterile (TGMS) rice variety could indeed be a way to improve the yield and cultivation efficiency of glutinous rice. Among them, the two-line system operates by crossing a TGMS line, which is sterile at high temperatures but fertile at lower temperatures, with a normal fertile line. In this study, we conducted to access morphological characteristics and combining ability of some glutinous TGMS lines. The parental lines were characterized on 13 agronomic traits including growth duration, plant height, flag leaf width, flag leaf length, panicle length, rachis length, number of primary branches, number of secondary branches, number of panicles per plant, percentage of filled grains, P1000 seeds, grain yield, and amylose content. The obtained results revealed significant variations in growth traits, yield, and amylose content of studied rice lines. Hierarchical clustering based on principal component analysis of rice lines on all measured traits showed three major clusters with high genetic diversity. Furthermore, fifteen glutinous TGMS rice lines and three testers were used in a Line x Tester mating system to produce 45 hybrids. The 45 hybrids were evaluated on 6 traits related to grain yield and morphology in a randomized complete block design experiment with three replications. A line x tester analysis was conducted to estimate the combining ability, genetic variance, and the contribution of parental lines to genetic variation in hybrids. These findings were valuable for rice breeders to orient the strategy for breeding of hybrid glutinous rice varieties with high efficiency.

The study was conducted to determine the effects of cultivars susceptibility to infection with the pathogenic isolates on the pathogenicity of rice kernel smut fungus (Tilletia barclayana). Rice (Oryza sativa L.) cultivars vary in susceptibility to kernel smut disease. The susceptibility of 18 commercial rice cultivars to T. barclayana was evaluated. Moreover, pathogenicity of 46 isolates of T. barclayana which had been isolated from six governorates in Egypt was studied using Giza 178 rice cultivar and Hybrid 1. The activities of certain oxidative enzymes, e.g. peroxidase (POX) and polyphenoloxidase (PPO) and total protein were determined in healthy and inoculated cultivars. Intron-exon splice junctions (ISJ) protocol was used to study the relationship among rice cultivars differing in their susceptibility to infection with the pathogen. Results showed that Giza 178 rice cultivar and Hybrid 1 were the most susceptible cultivars for rice kernel smut disease. Isolate no. 35 from the pathogenic fungus was the most aggressive isolate. Additionally, an increment in the defense-related enzymes and total protein was observed in rice cultivars as a result of inoculation with T. barclayana. ISJ technique showed the relationship between the studied rice cultivars and lines upon susceptibility to T. barclayana. It can also differentiate between the isolated T. barclayana isolates upon virulence on the studied rice cultivars and lines. Key words: Rice kernel smut disease, intron-exon splice junctions, rice, enzymes activity.

Abstract. Taryono, Supriyanta, Wulandari RA, Nurmansyah, Ambarwati E, Arsana IGKD, Aristya VE, Purba AE, Aisya AW, Alam T. 2023. Selection of drought-tolerant rice genotypes under cajuput (Melaleuca cajuputi subsp. cajuputi) agroforestry system. Biodiversitas 24: 4791-4802. Rice production can be increased by expanding rice cultivation area on agroforestry land. However, planting rice in agroforestry system, which is generally rainfed, might cause drought stress and eventually can reduce rice yields. The study aimed to select rice genotypes under drought stress conditions in a rainfed agroforestry system with cajuput or kayu putih (Melaleuca cajuputi subsp. cajuputi Powell). Ten promising rice lines and four control cultivars were grown during the dry season from March-July 2022 at the Menggoran Forest Management Resort, Playen Forest Section, Yogyakarta Forest Management, Indonesia. The observation was conducted on drought stress tolerance (sensitivity and recovery), molecular identification, and yield of rice cultivars. The results showed that G5 was the genotype with drought tolerance and had the best recovery compared to the other promising rice lines and control cultivars. The molecular identification of the 14 rice genotypes using 20 SSR markers detected 108 alleles with a PIC value of 0.707. The G5, G4, and G9 had higher yields than the control cultivars. The BLUE showed that the yield of G5, G4, and G9 were 6.59, 5.93 and 5.50 tons ha-1, respectively, while for BLUP by 6.45, 5.87 and 5.43 tons ha-1, respectively. Furthermore, there were four clusters consisting of cluster 1 (G9), cluster 2 (G7), cluster 3 (G5 and Inpago 12), and cluster 4 (Inpari 42, G6, Inpari 30 Ciherang Sub 1, Situ Bagendit, G3, G4, G10, G2, G1, and G8). The findings of this study recommend G4, G5, and G9 as promising rice lines which tolerant to drought stress under M. cajuputi agroforestry system and can be utilized in future plant breeding programs.

The research experiment conducted on the farmer paddy field in Ranomeeto village, District of South Konawe, Indonesia from January to May 2022, to evaluate the yield attributing characters and the grain yield in some new promising lines or cultivar of red rice. The red rice lines tested are GS12-1, GS12-2, GS16-1, GS16-2, GS44-1, and control variety Inpari-33, were laid out and arranged in field using randomized complete block design (RCBD) in three replications. The parameter measured were plant height, tiller density, productive tiller density, flowering time, harvesting times, panicle length, panicle density, filled grain percentage, 1000-grain weight, and grain yield. Differences between promising lines of red rice were found to exist when data on various yield-attributing features and grain yield were analysed. GS16-1 (89.37 cm) was the tallest plant and GS12-2 the shortest (72.74 cm). GS16-2 had the longest panicle (25.96 cm) and most grains per panicle (146.62). GS44-1 full grains, 1000-grain weight, and grain yield were highest. G12-1 lines had the most productive tillers, days to flowering, and harvest. Tiller number and productivity are positively correlated (0.908**). Tillers, productive tillers, and full grains percentage positively affect grain yield per plant.