Dry Matter Partitioning in Garden Pea (Pisum sativum L.) As Influenced by Different Light Levels

Low light responses of eight garden pea genotypes were investigated in the present experiment in terms of dry matter accumulation and partitioning in the plant. The light treatments consisted of (i) 100% photosynthetically active radiation (PAR) measured in the open field and (ii) 25%, (iii) 50%, (iv) 75% reduction of natural PAR obtained by using mosquito nets of variable color and mesh number. Among the genotype tested in the experiment Per cent of dry matter allocation to leaf and stem was increased in IPSA1, P30, P51 and local white due to reduction of PAR, whereas it was decreased in rest of the genotypes. Reducing light levels to 25% PAR also increased the percent dry matter investment to seed, such as IPSA1, IPSA2, IPSA3 and J1, whereas the investment to seed was less affected by reducing light treatment in P51 and local white. Most of the genotypes (e.g. IPSA3, P30, P51, P52 and local white) showed increased total dry matter production (TDM) under 75% PAR level compared to 100% but reduced with further reduction of PAR. The highest quantity of reduction in TDM under 25% PAR level was found in IPSA3 (about 80%). The results lead to suggest that among the eight garden pea genotypes tested in the present experiment P30 and local white performed better under low light environment whereas IPSA3 was found as sensitive to reducing light intensity.