Photosynthetic pigments content and chloroplast characteristics of tamarind leaves in response to different colored shading nets

Abstract

The use of coloured shading nets to improve plant development is a technique, which has received considerable recent interest due to positive responses obtained. In this context, photosynthetic pigments content and chloroplast characteristics of tamarind (Tamarindus indica) plants grown under coloured shade nets were examined. Under greenhouse, tamarind seeds were sown in polypropylene trays containing Plantmax® substrate. When the seedlings reached 10 cm long (approximately 60 d old), they were placed inside of structures covered with blue, red, white and black shade nets, with 50% of shading. After 150 d, the leaves were collected and chlorophyll and carotenoids content as well as chloroplast features were assessed. Plants grown under black net showed higher values for chlorophyll a and chlorophyll b content as well as for total chlorophyll and a/b ratio. The black net was also responsible for providing the highest density of chloroplasts and area of starch grains, while the chloroplast area was greater under blue and black nets. These results make the use of black net, a cultivation practice suitable for commercial purposes.