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ARS Home » Plains Area » Fort Collins, Colorado » Center for Agricultural Resources Research » Agricultural Genetic Resources Preservation Research » Research » Publications at this Location » Publication #406000
Research Project: Curation and Research to Safeguard and Expand Collections of Plant and Microbial Genetic Resources and Associated Descriptive Information

Location: Agricultural Genetic Resources Preservation Research

Title: Genetic variation and response to selection of photosynthetic and forage characteristics in Kentucky bluegrass (Poa pratensis L.) ecotypes under drought conditions

Author
item SHARIATIPOUR, NIKWAN - Shiraz University
item SHAMS, ZAHRA - Shiraz University
item HEIDARI, BAHRAM - Shiraz University
item Richards, Christopher

Submitted to: Frontiers in Plant Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/24/2023
Publication Date: 11/10/2023
Citation: Shariatipour, N., Shams, Z., Heidari, B., Richards, C.M. 2023. Genetic variation and response to selection of photosynthetic and forage characteristics in Kentucky bluegrass (Poa pratensis L.) ecotypes under drought conditions. Frontiers in Plant Science. 14. Article e1239860. https://doi.org/10.3389/fpls.2023.1239860.
DOI: https://doi.org/10.3389/fpls.2023.1239860

Interpretive Summary: This study examined the quantitative genetics and heritability of yield and photosynthetic rates in 100 genetic clones of naturally occurring Kentucky bluegrass samples grown under drought conditions. Field trails using two irrigation conditions over two growing season were conducted to evaluate the trade offs between photosynthetic efficiency and yield. In addition the study made use of 100 native collected samples which provided variation critical to breeding programs. Wide variation observed for traits in these ecotypic variants helped to select good candidates and develop segregating populations through cross-breeding programs to produce drought-tolerant varieties with higher forage yield traits and identify information about traits.

Technical Abstract: Assessment for the effects of drought stress on the photosynthetic characteristics and forage yield of Kentucky bluegrass (Poa pratensis L.) is important for enhancing the forage productivity and drought tolerance of Kentucky bluegrass. In the present study, the vegetative clone samples of 100 P. pratensis accessions collected from diverse geographic area of Iran were evaluated under two irrigation regimes (non-stress and drought stress). Genetic variation and response to selection for the photosynthetic characteristics [i.e. net photosynthesis rate (A), stomatal conductance (gs), transpiration rate (Tr), chlorophyll content (Chl), photochemical efficiency (Fv/Fm)] and forage yield [fresh forage yield (FY), dry forage yield (Dy)] traits were analyzed in two growing season (2018 and 2019).Drought stress had negative effects on fresh and dry forage yields and significantly reduced photosynthetic parameters. On average, FY with 45% decrease and gs with 326% decrease under drought stress condition showed the highest reduction rate among forage yield and photosynthesis traits, respectively. Genotypic coefficients of variation (GCV) for FY were lower under drought stress. The estimates of heritability, genetic advance and genetic advance as percentage of mean showed the predominance of additive gene action for the traits. Overall, the results showed that 'Ciakhor', 'Damavand', 'Karvandan', 'Basmenj', 'Abr2', 'Abrumand', 'Borhan', 'Hezarkanian', 'LasemCheshmeh', 'Torshab' and 'DoSar' showing little change between two conditions and higher yield can be promising candidates for developing high-yielding drought tolerant varieties through breeding programs.