Screening of Plantago species for physiological parameters in relation to seed yield

Isabgol is a major export oriented medicinal crop of India. The genetic variability available in this crop is limited owing to the narrow gene pool existing in our country. The physiological and growth characteristics of selected 7 species of Plantago were studied at DMAPR, Boriavi to investigate the relationship with the seed yield. Among the species studied, the lowest SLA (specific leaf area) of 0.15 cm2 g-1 was noticed in P. lanceolate. SLW (specific leaf weight) was recorded the lowest in P. coronopus (4.82 g cm-2) which was at par with P. indica. LAI also varied significantly among the species studied with the lowest being in P. arenaria (2.16) and P. serraria had the highest LAI (3. 87) among the species studied. P. ovata produced the highest biomass (21.49 g plant-1), while P. psyllium had comparable DM, however produced low seed yield (1.09 g plant-1) with HI of 0.061. P. lanceolate and P. ovata showed higher thousand seed weight among the species. P. indica (29.99 >mol CO2 m-2s-1) had the highest net photosynthetic rate among the species. Pn values for all the studied species were negatively correlated with their mean area of individual leaf (R2 0.366) and also with mean dry weight of leaves (R2 0.366). However, total biomass of plant was positively correlated with seed yield (R2 0.366). Thousand seed weight of studied species were significantly and positively correlated with the seed yield per plant (R2 0.771). In conclusion, leaf characteristics like high SLA, Pn , gs and TSW will positively contribute to the seed yield. These characters may be considered in the breeding programmes for the yield improvement of isabgol.