Effects of Different Shading Rates on the Photosynthesis and Corm Weight of Konjac Plant
Keywords:chlorophyll fluorescence parameter; konjac; photosynthesis; shading
To study the effects of shading level on the photosynthesis and corm weight of konjac plant, the chlorophyll fluorescence parameters, daily variation of relative electron transport rate (rETR), net photosynthetic rate (Pn), and corm weight of konjac plants under different treatments were measured and comparatively analyzed through covered cultivation of biennial seed corms with shade nets at different shading rates (0%, 50%, 70%, and 90%). The results showed that with the increase in shading rate, the maximum photochemical efficiency, potential activity, and non-photochemical quenching of photosystem Ⅱ (PSⅡ) of konjac leaves constantly increased, whereas the actual photosynthetic efficiency, rETR, and photochemical quenching of PSⅡ initially increased and then decreased. This result indicated that moderate shading could enhance the photosynthetic efficiency of konjac leaves. The daily variation of rETR in konjac plants under unshaded treatment showed a bimodal curve, whereas that under shaded treatment displayed a unimodal curve. The rETR of plants with 50% treatment and 70% treatment was gradually higher than that under unshaded treatment around noon. The moderate shading could increase the Pn of konjac leaves. The stomatal conductance and transpiration rate of the leaves under shaded treatment were significantly higher than those of the leaves under unshaded treatment. Shading could promote the growth of plants and increase corm weight. The comprehensive comparison shows that the konjac plants had strong photosynthetic capacity and high yield when the shading rate was 50%-70% for the area.
Baker NR (2008). Chlorophyll fluorescence: a probe of photosynthesis in vivo. Annual Review of Plant Biology 59:89-113.
Bepete M, Lakso AN (1998). Differential effects of shade on early-season fruit and shoot growth rates in ‘Empire’ apple. HortScience 33(5):823-825.
Bjorkman O, Demming B (1987). Photon yield of O2 evolution and chlorophyll ﬂuorescence characteristics at 77 K among vascular plants of diverse origins. Planta 170(4):489-504.
Chua M, Baldwin, TC, Hocking TJ, Chan K (2010). Traditional uses and potential health benefits of Amorphophallus konjac K. Koch ex NE Br. Journal of Ethnopharmacology 128(2):268-278.
Dai Y, Shen Z, Liu Y, Wang L, Hannaway D, Lu H (2009). Effects of shade treatments on the photosynthetic capacity, chlorophyll fluorescence, and chlorophyll content of Tetrastigma hemsleyanum Diels et Gilg. Environmental and Experimental Botany 65(2-3):177-182.
Douglas JA, Follett JM, Waller JE (2005). Research on konjac (Amorphophallus konjac) production in New Zealand. Acta Horticulturae 670:173-180.
Evans JR (2013). Improving photosynthesis. Plant Physiology 162(4):1780-1793.
Fu Z, Xie SQ, Xu WG, Yan S, Chen JW (2016). Characteristics of photosynthesis and chlorophyll a fluorescence in Amorphophallus albus during vigorous growth under different light intensity. Chinese Journal of Applied & Environmental Biology 22(2):446-454.
Genty B, Briantais JM, Baker NR (1989). The relationship between the quantum yield of photosynthetic electron transport and quenching of chlorophyll fluorescence. Biochimica et Biophysica Acta (BBA)-General Subjects 990(1):87-92.
Harjoko D, Sakya AT, Widijanto H (2016). The influence of shading intensity and foliar fertilizer concentration on growth and yield of konjac (Amorphophallus oncophyllus). In: The 2nd International Rainforest Conference - Climate Change Mitigation through Sustainable Rainforest Farming and Community-Based Livelihood. Surakarta, Indonesia pp 106-110.
Inaba K (1984). Effect of shading on leaf anatomy in Konjak plant (Amorphophallus konjac K. Koch). Japanese Journal of Crop Science 53(3):243-248.
Inaba K, Chonan N (1984). The effect of light intensity on ultrastructure of chloroplasts in Konjak (Amorphophallus konjac K. Koch). Japanese Journal of Crop Science 53(4):503-509.
Inoue T, Inanaga S, Sugimoto Y, El Siddig K (2004). Contribution of pre-anthesis assimilates and current photosynthesis to grain yield, and their relationships to drought resistance in wheat cultivars grown under different soil moisture. Photosynthetica 42(1):99-104.
Koblizek M, Kaftan D, Nedbal L (2001). On the relationship between the non-photochemical quenching of the chlorophyll fluorescence and the Photosystem Ⅱ light harvesting efficiency. A repetitive flash fluorescence induction study. Photosynthesis Research 68(2):141-152.
Li YM, Hu YH, Lv HZ, Zhao YX, Zhang JP (2001). A preliminary study on photosynthetic performance during tuber expansion period of elephant-yam (Amorphophallus rivieri Durieu) grown in the north of China. Journal of Agricultural University of Hebei 24(4):1-4.
Liu PY, Chen JF (1984). Research on photosynthetic capacity of elephant-foot yam. Journal of Southwest Agricultural College 4:21-26.
Liu PY (2004). Konjac. Chinese Agriculture Press, Beijing.
Mauro RP, Occhipinti A, Longo AMG, Mauromicale G (2011). Effects of shading on chlorophyll content, chlorophyll fluorescence and photosynthesis of subterranean clover. Journal of Agronomy and Crop Science 197(1):57-66.
Miura K, Osada A (1981). Effect of shading on photosynthesis, respiration, leaf area and corm weight in konjak plants (Amorphophallus konjak K. Koch). Japanese Journal of Crop Science 50(4):553-559.
Murchie EH, Lawson T (2013). Chlorophyll fluorescence analysis: a guide to good practice and understanding some new applications. Journal of Experimental Botany 64(13):3983-3998.
Roháček K (2002). Chlorophyll fluorescence parameters: the definitions, photosynthetic meaning, and mutual relationships. Photosynthetica 40(1):13-29.
Santosa E, Sugiyama N, Nakata M, Lee ON (2006). Growth and corm production of Amorphophallus at different shading levels in Indonesia. Japanese Journal of Tropical Agriculture 50(2):87-91.
Schreiber U, Bilger W, Neubauer C (1995). Chlorophyll fluorescence as a nonintrusive indicator for rapid assessment of in vivo photosynthesis. In: Schulze ED, Caldwell MM (Eds). Ecophysiology of photosynthesis. Springer, Berlin, Heidelberg, pp 49-70.
Seo GS, Lee JY, Song NH, Sin BW, Lee HD (1988). Effect of shading and mulching materials on the characteristics and yield of elephant food (Amorphophallus konjac). The Research Reports of The Rural Development Administration-Upland and Industrial Crops 30(2):74-78.
van Kooten O, Snel JFH (1990). The use of chlorophyll fluorescence nomenclature in plant stress physiology. Photosynthesis Research 25(3):147-150.
Xu M, Feng X, Hu P (2011). Effects of different shading degrees on konjac soft rot. Hubei Agricultural Sciences 50(23):4856-4857.
Yang AJ, Anjum SA, Wang L, Song JX, Zong XF, Lv J, … Dong YF (2018). Effect of foliar application of brassinolide on photosynthesis and chlorophyll fluorescence traits of Leymus chinensis under varying levels of shade. Photosynthetica 56(3):873-883.
Zhang Y, Xie B, Gan X (2005). Advance in the applications of konjac glucomannan and its derivatives. Carbohydrate Polymers 60(1):27-31.
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