Poster22: Widening the genetic basis of colombian irrigated rice germoplasm

Widening the Genetic Basis of Colombian Irrigated Rice Germplasm Pre-breeding, a strategic phase of genetic improvement because provides the raw material for further advance, is the transference of valuable traits from exotic to elite germplasm; exotic germplasm is a useful source of alleles when in existing cultivated gene pools the necessary allelic variation for breeding is lacking. Because this donor germplasm generally is inferior in agronomic performance, pre-breeding work is a difficult, long term and often unsuccessful process. CIAT rice breeding program is concentrated in pre-breeding work to develop enhanced germplasm for rice breeding programs in LAC, contributing to an eco-efficient rice production. With funding from the Ministry of Agriculture of Colombia and Fedearroz we are focusing on broadening the genetic base of irrigated rice for Colombian conditions using different pre-breeding strategies. Our commitment is to produce F 5 , and double haploid lines and one synthetic population after four years using 46 exotic parents of diverse origin, and 15 elite lines from FLAR. Introduction Material and Methods Results and discussion We are now producing breeding populations according with the scheme proposed in Figure 1 . Conclusions Future directions Fig 9. Genotypes with tolerance to Sheath Blight; average over three reps, under green house conditions. Fig 1. General breeding scheme. Two approaches were used to assess genetic diversity, pedigree analysis and principal component analysis based on agronomic, yield and yield related traits. Results were very similar reflecting differences between indica and japonicas with FLAR and CIAT lines as more related and colombian landraces as more diverse. This fact support the existence of considerable diversity specially between FLAR lines and Colombian landraces. Therefore, this exotic germplasm represents an opportunity to widening the genetic basis, thus contributing to an eco-efficient rice sector. A general breeding scheme is shown in Fig 1 . After phenotypic characterization, different crossing and selection strategies will be followed to produce pedigree and DH lines and a synthetic population. Figures 5 and 6 show the general distribution for grain yield in two locations. In general, elite lines had higher yields across locations than exotic material; however, some exotic lines like Pankaj, Palmar, Araure 3, Eloni, CT19558-2-17-1-4-3-M, and CT19298(83)-1-13-2-1-M had good yields. Elite lines FL04168-3P-12-2P-2P-M, FL03787-3P-5-1P-2P-M, FL03187-16P-11-2P-3P-M-1P-M, FL05564-8P-1-2P-2P-M, and FL06613-20P-2AI-2P-2P-M had higher yields than checks in both locations. Checks were T1=FL06733, T2=F-50, T3=F-473 and T4=F-60 In terms of grain quality, USA varieties Cocodrie, Cypress and Drew had the best performance in the percentage of whole grain, Figures 7 and 8. For blast resistance, several exotics like: Cypress, Tres Marias, CT18726-1-3-3-3-3, CT18247-12-8-1-2-2-3, CT18247-23-2-2-1-3-2, CT18526-15-2-1-1, CT18528-12-1-1-3, CT19558-2-17-1-4-3-M, and elite ones as: FL00147-8P-6-15P-M, FL03174-8P-7-2P-2P-M, FL04168-3P-12-2P-2P-M, FL05372-7P-1-2P-1P-M, FL05372-7P-4-4P-M-2PY, and FL05516-8P-3-5P-1P-M were highly resistant to leaf and neck blast under field conditions in Santa Rosa. The most tolerant Sheath Blight genotype under greenhouse conditions was Araure 3; other materials like CT15068-5-10-1-1, Palmar, Ligerito Playero and FL00147-8P-6-15P-M had a tolerant reaction ( Figure 9). Several genotypes had good resistance to Hoja Blanca Virus including CT17238-1-1-1-2-1-7-1, CT18247-23-2-2-1-3-2, FL05372-7P-4-4P-M-2PY, FL05516-8P-3-5P-1P-M, FL05564-8P-1-2P-2P-M, FL06883-9P-6-5P-5P-M and FL06885-4P-3-2P-2P-M. Some materials with high resistance to Tagosodes oryzicoulus, vector of RHBV, were observed including CT15081-6-10-2-2, Jasmine, Tres Marias, CT18247-12-8-1-2-2-3, CT19298(83)-1-13-2-1-M, FL03188-7P-5-3P-1P-M, FL03191-5P-13-3P-3P-M, FL05516-8P-3-5P-1P-M, FL06883-9P-6-5P-5P-M, and FL06885-4P-3-2P-2P-M. Most materials had intermediate or high amylose content with the exception of Jasmine and CT19558-2-17-1-4-3-M For days to 50% flowering, exotic materials were more precocious and Cocodrie, Cypress and Tres Marias had less than 80 days to flowering. Colombian landraces, Palawan, and Suakoko were tall materials whilst Cocodrie, Cypress and FL05372 were the shortest ones. Elites lines like FL06885-4P-3-2P-2P-M, FL03191-5P-13-3P-3P-M, FL03174-8P-7-2P-2P-M and the exotic Pankaj, were high tillering. CT lines CT18528-12-1-1-3 and CT18528-12-1-1-4, Colombian landraces Miramono, Monolaya, Inamono, and Cola de Vaca, and FLAR line FL06613-20P-2AI-2P-2P-M had the highest number of grains per panicles. Barthii derivates lines CT17238-1-1-1-2-1-7-1, CT17238-1-1-1-2-4-3-3, CT17238-1-1-1-2-4-4-2, CT15068-5-10-1-1, and CT15081-6-10-2-2 had heavier grains.

.- There is high divergence between exotic and elite materials

.- Several donors for valuables commercial traits were identified

.- There are good opportunities for development of eco-efficient rice lines

Acknowledgment: Colombian Ministry of Agriculture MADR, Colombian National Rice Federation-FEDEARROZ, FLAR and CIAT-Rice Program. Fig 4 Dendogram using parentage coefficient as genetic distance, UPGMA Fig 3. Dendogram using Principal Component Analysis Libertad y Orden Ministerio de Agricultura y Desarrollo Rural Torres, E.A.; Carabali, S.J.; Agredo, M.; Amezquita, N.; Borrero, J. and Martinez C.P. International Center for Tropical Agriculture (CIAT), AA 6713, Cali, Colombia [email_address] 24.0 % T1 T3 T2 T4 Fig 5. Grain yield (kg ha -1 ) distribution in Palmira. Fig 6. Grain yield (kg ha-1) distribution in Saldaña 4.0 % T1 T3 T2 T4 42.4 % T4 T2 T1 T3 Fig 7. Whole grain (%) distribution in Palmira 36.1 % T4 T2 T1 T3 Fig 8. Whole grain (%) distribution in Saldaña 1.- Phenotypic characterization of exotic and elite lines for yield, grain quality, agronomic traits, disease and insect reaction in three sites and controlled conditions 2.- Phenotypic characterization of three recurrent selection populations in Santa Rosa for disease reactions and grain quality 4.- A modified backcross strategy to produce breeding populations 3.- Estimation of genetic parameters in 3 recurrent selection populations for grain yield and quality, agronomic traits, disease and insect reaction using a nested design (NCI) 6.- Selection using pedigree and shuttle breeding in two contrasting locations 7.- Anther culture of selected BC 1 F 1 populations to fixed lines 9.- BC 1 F 5 lines 11.- Improved synthetic population 8.- One complete cycle of recurrent selection using S 1 families 10.- Fixed DH lines 5.- Introgression of elite lines in one population using one backcross to produce a poli-cytoplasmatic recurrent selection population