Spatiotemporal Dynamics Oil Photosynthetic Pigments Of Reed Leaves In Two Habitats Of Songnen Plain

Plant leaves are the main place of photosynthesis, the content of photosynthetic pigmentin leaf is very important for the efficiency of photosynthesis. Chlorophyll is a vector forabsorption and energy transfer. The content of chlorophyll directly affects photosynthesis andthe accumulation of organic matter and it is a basic measure of plant photosynthesis.Carotenoid is the accessory pigments to protect chlorophyll. They are important indicators ofplant physiology. In this paper, the determination of three photosynthetic pigment contentsuch as chlorophyll a, chlorophyll b and carotenoid of different reed population leaves indifferent habitat were analyzed, to research that the temporal and spatial variation ofphotosynthetic pigment content of different reed leaf age in different habitats, to reveal thepotential photosynthetic productive capacity and the aging process of different leaf ages, andthe role of different age leaves on the growth and development of plants. The results showedthat:(1) In seasonal stagnant water habitats (H1) and no water the alkali spot habitat (H2),content of photosynthetic pigment in different leaf age of reed ramets were different. Fromlate June to mid July, there was no difference between lower age leaves and higher age leaveson the whole, but they were significantly different among middle age leaves. From late July tomid August, there were no difference between each age leaves basically. After late August, thecontent of chlorophyll in higher age leaves were consistent, but they were significantlydifferent from the lower age leaves. There was significant difference between lower ageleaves and other growth period with the time. Middle age leaves were no difference in thelater growth period, but they were significantly different from the early and middle age leaves.The higher age leaves of each period had no difference. This reflected that the lower ageleaves showed a obvious senescence process and the senescence of middle age leaves wereslower and higher age leaves leaves were no signs of senescence. Leaves of different ages ofphotosynthetic production capacity were consistent in space and time. Middle age leaves aremainly function leaves in the early growth period, but in the middle growth period, all theleaves showed consistent production capacity, and in the later period, the mainly functionleaves turned to the higher age leaves mainly. The content of photosynthetic pigments of reedleaves in H1was mainly higher than that in H2.(2) For chlorophyll a and b contents of different age leaves, it was quadratic curvevariation with first increase and then decrease in H1; in H2, it was quadratic curve variation with first increase and then decrease in rule of space before heading stage at mid August, andthen turned into a linear increase. With the process of time, the peak of the contents ofchlorophyll a and b corresponding to the leaf age increased, and the highest chlorophyllcontent decreased, carotenoid content in the early growth period had also quadratic curve withfirst increase and then decrease, and then turned into a linear increase. With the growthprocess of plant, the number of leaves increased and the photosynthetic potential of leavesconstantly moved up.(3) The photosynthetic pigments content of same leaf age of reed population ramets inheterogeneous habitats had obvious regular changes with time, but the law of changes andeven the changing nature were diverse. In H1, the contents of chlorophyll a and b from lowerto higher age leaves were quadratic curve variation with first increase and then decrease, andthen turned into a linear decrease, at last showed a linear increase in a small rate. Carotenoidcontent was quadratic curve variation with first increase and then decrease, and then turnedinto a linear increase. The contents of chlorophyll a, b in H2decreased in the whole growingseason. The content of carotenoid was mainly quadratic curve variation with first increase andthen decrease. It showed that with the growth process, in H1, younger level leaves graduallymatured and grew senescence then fell off, and photosynthesis leaves were concentrated inthe middle age leaves. When the higher age leaves were mature, they will be the mainfunction leaves in the later growth period; chlorophyll was linearly decreased, all the leaveshas been to provide nutrients for growth and development of plant in H2.(4) In the two habitats, the chlorophyll of flag leaf of reproductive ramets showed anincreasing trend in the sample within thirty days from mid August to mid September, and didnot show senescence. The content of photosynthetic pigment of flag leaf was H1>H2. Even inthe harsh conditions of H2, the flag leaf that enter the reproductive period had strong vitalityand productivity. Compared with favorable habitat conditions of H1, The difference was thesmaller to the later growing season.