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Assessment of Drought Tolerance in Sainfoin: Physiological and Drought Tolerance Indices
Author(s) -
Irani Sayareh,
Majidi Mohammad Mahdi,
Mirlohi Aghafakhr,
Zargar Mahnaz,
Karami Mostafa
Publication year - 2015
Publication title -
agronomy journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.752
H-Index - 131
eISSN - 1435-0645
pISSN - 0002-1962
DOI - 10.2134/agronj15.0131
Subject(s) - ecotype , apx , proline , drought tolerance , biology , dry matter , germplasm , chlorophyll , agronomy , carotenoid , water content , forage , horticulture , botany , catalase , antioxidant , biochemistry , geotechnical engineering , amino acid , engineering
The physiological basis of genetic variation in drought response and its association with forage yield and drought tolerance indices is not clear in sainfoin ( Onobrychis viciifolia Scop.). In this study, 100 sainfoin genotypes from 10 ecotypes were clonally propagated and evaluated under non‐stressed and water deficit conditions during 2 yr. Physiological traits including chlorophyll a, chlorophyll b, total chlorophyll, carotenoid content, proline content, relative water content (RWC), catalase (CAT), ascorbate peroxidase (APX), superoxide dismutase (SOD) activity, dry matter yield (DMY), and stress tolerance index (STI) were studied. Large genotypic variation was observed among ecotypes for most of the studied traits indicating that selection in this germplasm would be useful. The results showed that water deficit greatly influenced physiological traits that affected forage production. Water deficit decreased DMY and RWC while significantly increasing carotenoid content, free proline content, CAT, APX, and SOD activity in both years. The relationship between dry matter yield and STI with proline content showed that ecotypes with high DMY and STI under water deficit conditions had higher proline accumulation in their leaves. With regard to the STI and principal component analysis (PCA), ecotypes Baft, Najafabad, and Sirjan were found to be drought tolerant or moderately drought tolerant. These ecotypes showed significantly higher values for proline content under water deficit conditions.