Traditional rice varieties, modern released, improved and breeding lines were evaluated for blast resistance in identified outbreak hotspot areas and established National Cooperative Test (NCT) screening sites for major diseases of the rice. Line development using the conventional method was started from 89 F1 and successive selection resulted in 2758 breeding lines for further selection in the nurseries of origin. For direct sowing under field conditions, 29 populations and 14 breeding lines were identified that had early seedling vigor (SV) and anaerobic germination (AG).
In addition, 1,414 advanced breeding lines were designated for further line selection and 345 uniform lines were selected for advancement to the Observation Nursery (ON) in the Performance Trial. Generation of new superior crosses and breeding lines for preliminary evaluation under irrigated lowland ecosystem was carried out. 85 new crosses were generated using released cultivars and breeding lines with high yield and biotic and abiotic tolerance backgrounds.
This study identified breeding lines with high seedling vigor (SV), anaerobic tolerance (AG) under field and nursery conditions, and lodging resistance. There were 14 populations and 6 breeding lines with excellent early seeding vigor and anaerobic tolerance, while 15 populations and 8 breeding lines were identified with a good score. Nine advanced breeding lines had intermediate tolerance to anaerobic germination, and 12 had tolerance of resistant anaerobic seedlings under lamp conditions.
Four breeding lines showed intermediate seedling tolerance in screen conditions and positive for two SSR markers for anaerobic tolerance.
Marker-Assisted Selection for Pest and Disease Resistance Genes in Inbred Variety Development
Strong wind causes sticking of rice plants which affects the color and flavor of rice grain. The consequences of flooding during crop establishment and placement from flowering to maturity limit farmers in the use of direct seeding, especially during the rainy season. Under screen house screening, the use of MAS for anaerobic tolerance using two SSR markers was also used.
Meanwhile, rice lines useful as common donors of BB and tungro resistance genes will be shared in the PBBD hybridization block for use in breeding. Thirty-two individual plants also pyramided with Glh14, tsv1, Xa4, xa5, and Xa7/Xa21 were selected, but their responses to BB and tungro remain to be evaluated. This year, new F1 plants were also generated from crossing sensitive elite breeding lines and MAS-bred donor lines with BB and tungro resistance.
Putative F1 plants produced during the rainy season from 10 additional cross combinations were planted in house for DNA extraction and genotyping. The resulting F2 seeds from all true F1 plants will be collected for further selection and advancement.
Field Performance Trial of Advanced Breeding Lines
In PYT-DSR and TPR, 26 promising accessions with ≥10% YA over controls were identified for GYT. Overall performance resulted in 41 promising entries with ≥ 10% YA over controls and are potential entries for MET nomination.
Breeding of Specialty Rice
Development of Aromatic, Glutinous, Pigmented and Iron/
Zinc-dense Rice Varieties
The study is composed of breeding activities from the selection of parents, to line development from the segregating generations, to the evaluation of advanced lines in the performance trials, and to MET or NCT. Line selection in the hybrid populations and pedigree breeding resulted in 5,866 specialty-type lines for further selection and 261 uniform lines for progression to ON. From the performance trials, the majority of test entries passed the corresponding check by at least 10%.
The same 10% YA above the corresponding verification standard was used for entries assessed in PYT and GYT.
Evaluation and Utilization of Fragrance Markers for High- Yielding Aromatic Breeding Materials
Development of Rice Varieties Adapted to Rainfed and Stress Environments
Development of Rice Varieties Adapted to Stress Environments
To date, there are 74 NCT-ready breeding lines consisting of 58 RILs, 13 anther-derived lines, and 3 seed culture-derived lines with 5–10 kg of genetically pure seeds. Breeding lines are tolerant to drought, salinity, submergence or combinations of these stresses.
Mass Screen for Abiotic Stress
Consolidating the responses of tissue culture 231, in vitro mutagenesis and seed mutation-derived lines from Y Dam Do and Jepun have combined drought tolerance and salt lines from Salumpikit have salt and submergence tolerance, and 9 (3.9%) lines from NSIC Rc 222 were drought, salinity and submergence tolerant. Mass screening for abiotic stresses of early segregated populations in F2 and F2:3 identified putatively tolerant plants which were grown to maturity and seeds were obtained for use in the evaluation and further development of multi-abiotic tolerant breeding lines. stress.
Multi-environment and Adaptability Tests of Breeding Lines in Drought-Prone Rainfed Lowland
Combining Submergence, Stagnant and Salinity Tolerance into High Yielding Rice Varieties
Breeding for Heat-Tolerant Rice
From these lines, 75% of the selected early segregating populations and 78.5% of the advanced lines had ≥60% spikelet fertility. Uniform lines had a yield of 5.5-8.8t/ha under high temperature conditions and grain fertility of 60.1-85.7%. Fifteen promising rules were submitted to MET for 2020 evaluation and another six rules for NCT.
PBBD Research and Analytical Laboratory Systems and Maintenance
Basic Seed Production
Distinctness Uniformity and Stability Test
Union for the Protection of New Varieties of Plants (UPOV) guidelines, and ISTA at all growth stages were collected to identify the distinguishing characteristics, uniformity and stability of the promising lines. Passport data of these lines were generated according to the 56 UPOV and IRRI description for rice for quantitative and qualitative traits in all growth stages. The passport data will serve as a reference once the line is approved and released as a new variety.
Nucleus Seed Production
Breeder Seed Production
Extra pans were refrigerated for further planting for the next harvest seasons. Eight hundred panicles of high demand varieties and 400 pre-germinated panicles of other varieties were sown directly on wet beds, with 350 m2 allocated per List of varieties was submitted to NSQCS 20 days after transplanting for field inspection and certification as per the seed certification standards.
In order to ensure the genetic purity of the rice seeds, the treatment was carried out from the vegetative to the mature stage to facilitate the removal of all possible admixtures and diseased plants before harvesting. Cut panicles were removed from the plot to minimize seed shedding during threshing. The seeds were dried to 11-14% moisture content (MC) after threshing, as one or two days of seed storage without adequate drying will spoil the seeds, resulting in seed discoloration and reduced seed viability and vigor.
The dried seeds were cleaned using fans or grain cleaners to remove empty, light and diseased seeds, weed seeds, soil particles and other contaminants. However, the seeds for planting in the next season were stored in an air-conditioned room with a dehumidifier to maintain viability and vigor. In 2019, 66 varieties were planted in the PBBD seed production area, with a total yield of 13,730 kg for both irrigated and adverse environments.
In 2019, efficiency of 72.02% and 87.125% in DS and WS respectively was achieved in irrigated and noxious varieties based on NSQCS certification results. The seed production component aims to accelerate the identification and use of genotypes that can contribute to overcoming constraints in rice production. CGMS - Cytoplasmic Genetic Male Sterility COF - Commercial Organic Fertilizer CDA - Cooperative Development Authority DAS - Days after sowing.
DOLE - Ministry of Labor and Employment DTI - Ministry of Trade and Industry DSR - Rice with direct seeds. FGD - Focused group discussion FSP - Basic seed production FRK - On-farm record keeping GABA - Gamma-aminobutyric acid GT - Gelatinization temperature GAD - Gender and development GYT - General crop trial. ICT - Information and Communication Technology IEC - Information Education Communication IBNM - Inorganic Nutrient Management ICM - Integrated Crop Management.
