A pot experiment was conducted at the Botany Department, ., Aligarh, on 2 root crop plants, viz. turnip (Brassica rapa L.), non-sugar-producing and sugar beet (Beta vulgaris L.), sugar-producing, to compare their physiological activity (Hill activity, photosynthesis and chlorophyll content). | Turk J Biol 30 (2006) 153-155 © TÜB‹TAK Hill Reaction, Photosynthesis and Chlorophyll Content in Non-Sugar-Producing (Turnip, Brassica rapa L.) and Sugar-Producing (Sugar beet, Beta vulgaris L.) Root Crop Plants Manzer H. SIDDIQUI, M. Masroor A. KHAN, M. Nasir KHAN, Firoz MOHAMMAD, M. NAEEM Plant Physiology Section, Department of Botany, Aligarh Muslim University, Aligarh, 202 002, INDIA Received: Abstract: A pot experiment was conducted at the Botany Department, ., Aligarh, on 2 root crop plants, viz. turnip (Brassica rapa L.), non-sugar-producing and sugar beet (Beta vulgaris L.), sugar-producing, to compare their physiological activity (Hill activity, photosynthesis and chlorophyll content). The seeds of each plant were sown in 20 pots (80% soil + 20% FYM) separately. Two samplings were done at 125 and 140 days (after sowing). Hill activity was measured spectrophotometrically using DCPIP indicator and photosynthesis was assayed by LICOR-6200 Photosynthesis System. Sugar beet gave the maximum leaf-area, Chl a/b ratio, stomatal conductance and photosynthesis rate and Hill activity at 125 days. However, the total chlorophyll was higher in turnip at both stages than sugar beet. The stomatal resistance was maximum in turnip at 140 days and minimum in sugar beet at 125 days. The data show that chlorophyll contents are not related to the photosynthesis rate. The latter was most profound in sugar beet at both stages as considerable amounts of photosynthates are transformed into sucrose and therefore sugar beet contains over 20% sugar by weight. Key Words: Hill activity, photosynthesis, turnip, sugar beet Introduction The sun’s radiant energy is captured and stored by organisms, viz. plants, algae, and a few species of bacteria, which all have specialised pigments. These organisms have the ability to manufacture carbohydrate in the presence of light through the process of photosynthesis. The photosynthetic efficiency of plants is also considerably .
