Correlation between morphological characteristics and heat tolerance in nine cultivars of forage pea

Description

Pea (Pisum sativum L.) is a vital legume crop, essential for human consumption, animal forage, and soil fertility improvement. In this study, nine pea cultivars, comprising spring (ssp. sativum) and winter (ssp. arvense) types were studied. The photosynthetic activity under normal (20 ◦C, morning) and high (30 ◦C, midday) temperature was measured in June 2025 by the method of chlorophyll fluorescence. Subsequently, the calculated OJIP parameters were compared to some morphological characteristics of the cultivars, such as amount of leaflets per node, stem height and biomass yield. The correlation between fluorescence and morphological parameters at the different temperatures was calculated to determine the more important traits for pea tolerance to higher temperatures. It was found out, that under 20 ◦C the correlations between photosynthesis and morphological traits were negligible for the most of the studied parameters. One of the exceptions was Fo, which strongly correlated to the amount of leaflets per node. However, after 30 ◦C, the correlation strength increased drastically, implying more active photosynthesis, and thus higher stress tolerance of the cultivars with longer stem and more leaves. These pea plants had significantly higher quantum efficiency of the primary photochemistry (ϕPo) and the electron transport (ϕEo), both of which are known to be affected the most during heat stress.

Institutions

• Agricultural Academy

  Sofia-Capital, Sofia
• Institute of Forage Crops

  Pleven, Pleven

Categories

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