Phenotypic response of farmer‐selected CWR‐derived rice lines to salt stress in the Mekong Delta

Abstract

Breeding for salt tolerance or abiotic stress, in general, requires rapid but reliable screening protocols that reflect the actual field situation as much as possible. A collection of 200 crop wild relative (CWR)-derived BC 3 F 3-4 rice (Oryza sativa L.) lines developed at the International Rice Research Institute (IRRI) were evaluated by farmers in the Mekong Delta over two seasons for agronomic performance. Fifty stable BC 3 F 5 lines were selected and subsequently screened in hydroponics using three NaCl concentrations to assess their phenotypic response to salt stress. The lines and check varieties were grown in a salinized Yoshida nutrient solution at three concentrations: 68, 102, and 13 mM NaCl. Several lines were identified to be tolerant to salinity stress and ANOVA showed significant differences among genotypes and NaCl concentrations. Root and shoot growth parameters showed an inverse relationship with increasing NaCl concentration. Population genetic analysis suggested four groups of genotypes, where the median salt injury score across the three NaCl concentrations was identified as the main clustering factor. Lines from Cluster 3 were identified as the most promising donors of salt tolerance.

Participatory selection of CWR‐derived salt‐tolerant rice lines adapted to the coastal zone of the Mekong Delta

“…A total of 200 BC 3 F 3B lines were received from IRRI in December 2018 and approved by the Vietnamese quarantine authorities for release into the environment. The 200 lines were distributed to 13 seed clubs in eight provinces in the Mekong Delta region for participatory on‐farm selection (Tin et al., 2020).…”

“…Four widely different accessions were selected from the International Rice Genebank Collection at the International Rice Research Institute (IRRI), originating from Bangladesh (IRGC 103837), China (IRGC 100916), Malaysia (IRGC 105491), and Papua New Guinea (IRGC 106276). These were backcrossed over three generations into the modern elite variety IRRI 154 (released in the Philippines under the commercial name NSiC Rc 222) and self‐pollinated for two generations (Tin et al., 2020).…”

“…Details about the first growing season in the Mekong Delta (December 2018 -May 2019) and the selected lines are provided by Tin et al 2020. In total, 1027 BC 3 F 4 lines were selected for the second growing season (April 2019 -November 2019), and distributed to 14 seed clubs in nine provinces in the Mekong Delta for further on-site evaluation by farmers.…”

Pressmud alleviates soil sodicity stress in a rice–wheat rotation: Effects on soil properties, physiological adaptation and yield‐related traits

“…PCA has previously been applied for detecting salt‐induced adaptive and metabolic changes in both rice (Tin et al, 2020) and wheat (Guo et al, 2015). Besides extracting the relevant information from large multivariate datasets, PCA is also widely used for identifying the traits/treatments explaining maximum variation in original data (Füzy et al, 2019).…”

Crop Science special issue: Adapting agriculture to climate change: A walk on the wild side

“…We took two such studies on board for this special issue of Crop Science : Tin et al. (2021a), in “ Phenotypic response of farmer‐selected CWR‐derived rice lines to salt stress in the Mekong Delta ,” describe the development of CWR‐derived rice lines and their evaluation in the Mekong Delta. Subsequently, 50 stable BC 3 F 5 lines were selected by farmers and screened in hydroponics to assess their phenotypic response to salt stress.…”