Participatory evaluation guides the development and selection of farmers’ preferred rice varieties for salt- and flood-affected coastal deltas of South and Southeast Asia

Rice is the staple food and provides livelihood for smallholder farmers in the coastal delta regions of South and Southeast Asia. However, its productivity is often low because of several abiotic stresses including high soil salinity and waterlogging during the wet (monsoon) season and high soil and water salinity during the dry season. Development and dissemination of suitable rice varieties tolerant of these multiple stresses encountered in coastal zones are of prime importance for increasing and stabilizing rice productivity, however adoption of new varieties has been slow in this region. Here we implemented participatory varietal selection (PVS) processes to identify and understand smallholder farmers’ criteria for selection and adoption of new rice varieties in coastal zones. New breeding lines together with released rice varieties were evaluated in on-station and on-farm trials (researcher-managed) during the wet and dry seasons of 2008–2014 in the Indian Sundarbans region. Significant correlations between preferences of male and female farmers in most trials indicated that both groups have similar criteria for selection of rice varieties. However, farmers’ preference criteria were different from researchers’ criteria. Grain yield was important, but not the sole reason for variety selection by farmers. Several other factors also governed preferences and were strikingly different when compared across wet and dry seasons. For the wet season, farmers preferred tall (140–170cm), long duration (160–170 d), lodging resistant and high yielding rice varieties because these traits are required in lowlands where water stagnates in the field for about four months (July to October). For the dry season, farmers’ preferences were for high yielding, salt tolerant, early maturing (115–130 d) varieties with long slender grains and good quality for better market value. Pest and disease resistance was important in both seasons but did not rank high. When farmers ranked the two most preferred varieties, the ranking order was sometimes variable between locations and years, but when the top four varieties that consistently ranked high were considered, the variability was low. This indicates that at least 3–4 of the best-performing entries should be considered in succeeding multi-location and multi-year trials, thereby increasing the chances that the most stable varieties are selected. These findings will help improve breeding programs by providing information on critical traits. Selected varieties through PVS are also more likely to be adopted by farmers and will ensure higher and more stable productivity in the salt- and flood-affected coastal deltas of South and Southeast Asia

Analysis of Stability and G × E Interaction of Rice Genotypes across Saline and Alkaline Environments in India

Genotype × environment (G × E) interaction effects are of special interest for identifying the most suitable genotypes with respect to target environments, representative locations and other specific stresses. Twenty-two advanced breeding lines contributed by the national partners of the Salinity Tolerance Breeding Network (STBN) along with four checks were evaluated across 12 different salt affected sites comprising five coastal saline and seven alkaline environments in India. The study was conducted to assess the G × E interaction and stability of advanced breeding lines for yield and yield components using additive main effects and multiplicative interaction (AMMI) model. In the AMMI1 biplot, there were two mega-environments (ME) includes ME-A as CARI, KARAIKAL, TRICHY and NDUAT with winning genotype CSR 2K 262; and ME-B as KARSO, LUCKN, KARSA, GOA, CRRI, DRR, BIHAR and PANVE with winning genotypes CSR 36. Genotypes CSR 2K 262, CSR 27, NDRK 11-4, NDRK 11-3, NDRK 11-2, CSR 2K 255 and PNL 1-1-1-6-7-1 were identified as specifically adapted to favorable locations. The stability and adaptability of AMMI indicated that the best yielding genotypes were CSR 2K 262 for both coastal saline and alkaline environments and CSR 36 for alkaline environment. CARI and PANVEL were found as the most discernible environments for genotypic performance because of the greatest GE interaction. The genotype CSR 36 is specifically adapted to coastal saline environments GOA, KARSO, DRR, CRRI and BIHAR and while genotype CSR 2K 262 adapted to alkaline environments LUCKN, NDUAT, TRICH and KARAI. Use of most adapted lines could be used directly as varieties. Using them as donors for wide or specific adaptability with selection in the target environment offers the best opportunity for widening the genetic base of coastal salinity and alkalinity stress tolerance and development of adapted genotypes. Highly stable genotypes can improve the rice productivity in salt-affected areas and ensure livelihood of the resource poor farming communities

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Not AvailableSubmergence of lowland rice (Oryza sativa L.) fields during the wet season in coastal regions adversely affects survival and productivity of rice. A field experiment was conducted for two consecutive wet seasons in 2016 and 2017 at ICAR-Central Soil Salinity Research Institute, Regional Research Station, Canning Town, West Bengal to evaluate the performance of six varieties carrying the SUB1 gene (BR11-Sub1, Ciherang-Sub1, CR1009-Sub1, IR64- Sub1, Samba-Sub1, and Swarna-Sub1) along with two checks (DRR Dhan39 and Sabita) under stagnant and flash flooding situations. Sabita produced the highest grain yield (3.45 t/ha) followed by CR1009-Sub1 (3.27 t/ha) under stagnant flooding. Sabita is the local check under stagnant flooding. Under flash flooding, CR1009-Sub1 produced the highest grain yield of 4.11 t/ha, followed by Swarna-Sub1 (3.11 t/ha) and BR11-Sub1 (2.78 t/ha). Participatory varietal selection (PVS) was conducted during both the years to assess the preferences of farming communities for these varieties. Under stagnant flooding, the highest preference score was recorded for Sabita (0.62) followed by BR11-Sub1 (0.32) and CR1009-Sub1 (0.31). The lowest preference score was observed for IR64-Sub1 (-0.56), Samba-Sub1(-0.31), and Ciherang-Sub1 (-0.26). Under flash flooding, the highest preference score was recorded for CR1009-Sub1 (0.63) followed by BR11-Sub1 (0.38) and Swarna-Sub1 (0.20). The lowest preference score was observed for IR64-Sub1 (-0.62), Samba-Sub1 (-0.34), Ciherang-Sub1 (-0.29), and DRR Dhan39 (-0.27). Based on the results of field experiments and farmers’ preferences, CR1009-Sub1, BR11-Sub1, and Swarna-Sub1 could be recommended for cultivation in areas affected by flash floods in coastal areas of India.Not Availabl

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Not AvailableSubmergence of lowland rice (Oryza sativa L.) fields during the wet season in coastal regions adversely affects survival and productivity of rice. A field experiment was conducted for two consecutive wet seasons in 2016 and 2017 at ICAR-Central Soil Salinity Research Institute, Regional Research Station, Canning Town, West Bengal to evaluate the performance of six varieties carrying the SUB1 gene (BR11-Sub1, Ciherang-Sub1, CR1009-Sub1, IR64-Sub1, Samba-Sub1, and Swarna-Sub1) along with two checks (DRR Dhan39 and Sabita) under stagnant and flash flooding situations. Sabita produced the highest grain yield (3.45 t/ha) followed by CR1009-Sub1 (3.27 t/ha) under stagnant flooding. Sabita is the local check under stagnant flooding. Under flash flooding, CR1009-Sub1 produced the highest grain yield of 4.11 t/ha, followed by Swarna-Sub1 (3.11 t/ha) and BR11-Sub1 (2.78 t/ha). Participatory varietal selection (PVS) was conducted during both the years to assess the preferences of farming communities for these varieties. Under stagnant flooding, the highest preference score was recorded for Sabita (0.62) followed by BR11-Sub1 (0.32) and CR1009-Sub1 (0.31). The lowest preference score was observed for IR64-Sub1 (-0.56), Samba-Sub1(-0.31), and Ciherang-Sub1 (-0.26). Under flash flooding, the highest preference score was recorded for CR1009-Sub1 (0.63) followed by BR11-Sub1 (0.38) and Swarna-Sub1 (0.20). The lowest preference score was observed for IR64-Sub1 (-0.62), Samba-Sub1 (-0.34), Ciherang-Sub1 (-0.29), and DRR Dhan39 (-0.27). Based on the results of field experiments and farmers’ preferences, CR1009-Sub1, BR11-Sub1, and Swarna-Sub1 could be recommended for cultivation in areas affected by flash floods in coastal areas of India.Not Availabl

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Not AvailableIn the present study, a total of 53 promising salt-tolerant genotypes were tested across 18 salt-afected diverse locations for three years. An attempt was made to identify ideal test locations and megaenvironments using GGE biplot analysis. The CSSRI sodic environment was the most discriminating location in individual years as well as over the years and could be used to screen out unstable and saltsensitive genotypes. Genotypes CSR36, CSR-2K-219, and CSR-2K-262 were found ideal across years. Overall, Genotypes CSR-2K-219, CSR-2K-262, and CSR-2K-242 were found superior and stable among all genotypes with higher mean yields. Diferent sets of genotypes emerged as winners in saline soils but not in sodic soils; however, Genotype CSR-2K-262 was the only genotype that was best under both saline and alkaline environments over the years. The lack of repeatable associations among locations and repeatable mega-environment groupings indicated the complexity of soil salinity. Hence, a multilocation and multi-year evaluation is indispensable for evaluating the test sites as well as identifying genotypes with consistently specifc and wider adaptation to particular agro-climatic zones. The genotypes identifed in the present study could be used for commercial cultivation across edaphically challenged areas for sustainable production.Not Availabl