Coordination of root growth and leaf senescence in cotton
【Abstract】Two cotton cultivars, Baimian 1 and DP99B, were used to investigate the root growth and vigor, leaf senescence, and yield in the field during 2011–2012. Baimian 1 produced higher cotton fiber yield than DP99B during the two years. Baimian 1 had better leaf photosynthetic rate or performance index based on light energy absorption, higher root length density (RLD), better root distribution, and higher root vigor than DP99B, evidenced by higher volume of bleeding sap, in which higher percentage of protein was contained. In 2012, DP99B had faster root growth with higher RLD in middle August and higher root vigor in late July than Baimian 1. The total xylem sap amount of DP99B was 1.7 times that of Baimian 1. After the full-bloom stage, the higher root density, more bleeding sap, and slower leaf senescence showed coordination to a great extent, confirming that leaf senescence was regulated by root growth and root vigor in late cotton growth season.
【Keywords】 cotton; root distribution ; root length density ; bleeding sap ; leaf senescence ;
(Translated by GAO XP)
 Hodge A, Berta G, Doussan C, Francisco M, Crespi M. Plant root growth, architecture and function. Plant Soil, 2009, 321: 153–187.
 Zhang H, Xue Y G, Wang Z Q, Yang J C, Zhang J H. Morphological and physiological traits of roots and their relationships with shoot growth in “super” rice. Field Crops Res, 2009, 113: 31–40.
 Qi W Z, Liu H H, Liu P, Dong S T, Zhao B Q, So H B, Li G, Liu H D, Zhang J W, Zhao B. Morphological and physiological characteristics of corn (Zea mays L.) roots from cultivars with different yield potentials. Eur J Agron, 2012, 38: 54–63.
 Mu X H, Chen F J, Wu Q P, Chen Q W, Wang J F, Yuan L X, Mi G H. Genetic improvement of root growth increases maize yield via enhanced post-silking nitrogen uptake. Eur J Agron, 2015, 63: 55–61.
 Brouder S M, Cassman K G. Root development of two cotton cultivars in relation to potassium uptake and plant growth in a vermiculitic soil. Field Crops Res, 1990, 23: 187–203.
 Ling Q H, Lu W P, Cai J Z, Cao X Z. The relationship between root distribution and leaf angle in rice plant. Acta Agron Sin, 1989,15: 123–131 (in Chinese with English abstract).
 Kong L, Si J, Sun M, Feng B, Zhang B, Li S, Wang Z, Wang F. Deep roots are pivotal for regulating post-anthesis leaf senescence in wheat (Triticum aestivum L.). J Agron Crop Sci, 2013,199: 209–216.
 Wang Y L, Cai J Z, He J S, Chen L, Xu J K, Bian Y. The relationships between spikelet-root-activity and grain filling and ripening in rice (Oryza sativa). Acta Agron Sin, 1992, 18: 81–89 (in Chinese with English abstract).
 Pan X H, Wang Y R, Fu J R. Advance in the study on the growth-physiology in rice of root system (Oryza sativa). Chin Bull Bot, 1996, 13(2): 13–20 (in Chinese with English abstract).
 Yue S S, Yu Z W, Yu S L. Senescence of flag leaf and root in wheat. Acta Agron Sin, 1996, 22: 55–58 (in Chinese with English abstract).
 Zhang Z, Xin W, Wang S, Zhang X, Dai H F, Sun R R, Frazier T, Zhang B H, Wang Q L. Xylem sap in cotton contains proteins that contribute to environmental stress response and cell wall development. Funct Integr Genomic, 2015, 15: 17–26.
 Qiu H B, Pan Y C, Wang B B, Lu D Z. The relationship between leaf senescence and the flow intensity of xylem sap, yield of indica rice. J Zhejiang Agric Sci, 1981,(4): 175–178 (in Chinese with English abstract).
 Liang J S, Cao X Z. Studies on the relationship between several physiological characteristics of leaf and bleeding rate of roots in hybrid rice (O. sativa L.). J Jiangsu Agric Coll, 1993, 14(4): 25–30 (in Chinese with English abstract).
 Zhao Q Z, Huang P S, Ling Q H, Gao E M, Dong J S. The relationship between spikelet-bleeding-intensity and population quality of rice. J Nanjing Agric Univ, 2000, 23(3): 9–12 (in Chinese with English abstract).
 Xu F Y, Ma J, Wang H Z, Liu H Y, Huang Q L, Ma W B, Ming D F. The characteristics of roots and their relation to the formation of grain yield under the cultivation by system of rice intensification (SRI). Hybrid Rice, 2003, 18(4): 61–65 (in Chinese with English abstract).
 Chen Y Z, Dong H Z. Mechanisms and regulation of senescence and maturity performance in cotton. Field Crops Res, 2016, 189: 1–9.
 Chen Y Z, Kong X Q, Dong H Z. Removal of early fruiting branches impacts leaf senescence and yield by altering the sink/source ratio of field-grown cotton. Field Crops Res, 2018,216: 10–21.
 Dong H Z, Li W J, Tang W, Zhang D M. Research progress in physiological premature senescence in cotton. Cotton Sci, 2005, 17: 56–60 (in Chinese with English abstract).
 Wright P R. Premature senescence of cotton-predominantly a potassium disorder caused by an imbalance of source and sink. Plant Soil, 1999, 211: 231–239.
 Wang Y, Li B, Du M W, Eneji A E, Wang B M, Duan L S, Li Z H, Tian X L. Mechanism of phytohormone involvement in feedback regulation of cotton leaf senescence induced by potassium deﬁciency. J Exp Bot, 2012, 63: 5887–5901.
 Zhao J Q, Li S, Jiang T F, Liu Z, Zhang W W, Jian G L, Qi F J. Chilling stress: the key predisposing factor for causing Alternaria alternata infection and leading to cotton (Gossypium hirsutum L.) leaf senescence. PLoS One, 2012, 7: e36126.
 Kong X Q, Luo Z, Li C D, Dong H Z. Molecular mechanisms of premature senescence in cotton. Cotton Sci, 2015, 27: 71–79 (in Chinese with English abstract).
 Dong H Z, Niu Y H, Li W J, Tang W, Li Z H, Zhang D M. Regulation effects of various training modes on source-sink relation of cotton. Chin J Appl Ecol, 2008, 19: 819–824.
 Dai J L, Dong H Z. Stem girdling inﬂuences concentrations of endogenous cytokinins and abscisic acid in relation to leaf senescence in cotton. Acta Physiol Plant, 2011, 33: 1697–1705.
 Hu Z B, Wang S F, Zhang X, Zhang Z Y, Dai H F, Wang Q L. Differences of potassium efficiency and root responses to potassium deficiency between short- and long-season cotton genotypes. Acta Agric Boreali-Sin, 2014, 29(5): 218–225 (in Chinese with English abstract).
 Zhang Z Y, Tian X L, Duan L S, Wang B M, He Z P, Li Z H. Differential responses of conventional and Bt-transgenic cotton to potassium deficiency. J Plant Nutr, 2007, 30: 659–670.
 Cassman K G, Bryant D C, Higashi S L, Roberts B A, Kerby T A. Soil potassium balance and cumulative cotton response to annual additions on a vermiculitic soil. Soil Sci Soc Am J,1989, 53: 805–812.
 Duan J, Liang C Y, Huang Y W. Studies on leaf senescence of hybrid rice at blooming and grain formation stage. Acta Phytophysiol Sin, 1997, 23: 139–144 (in Chinese with English abstract).
 Nooden L D. Integration of soybean pod development and monocarpic senescence. Physiol Planta, 1984, 62: 273–284.
 Miceli F, Crafts-Brandner S J, Egli D B. Physical restriction of pod growth alters development of soybean plants. Crop Sci, 1995,35: 1081–1085.
 Huang S M. A study on the relationship between the leaf senescence and source sink ratio in hybrid rice. Acta Agric Univ Jiangxiensis, 2001, 23(2): 171–173 (in Chinese with English abstract).
 Zhao C Y, Yan Y Y, Yimamu Y, Li J Y. Effects of soil moisture on cotton root length density and yield under drip irrigation with plastic mulch in Aksu Oasis farmland. J Arid Land, 2010, 2: 243–249.
 Ning S R, Shi J C, Zuo Q, Wang S, Ben-Gal A. Generalization of the root length density distribution of cotton under film mulched drip irrigation. Field Crops Res, 2015, 177: 125–136.
 Chen J, Liu L T, Wang Z B, Sun H C, Zhang Y J, Lu Z Y, Li C D. Determining the effects of nitrogen rate on cotton root growth and distribution with soil cores and minirhizotrons. PLoS One, 2018, 13: e0197284.
 Yang X K, Zhang Z Q, Niu Y, Tian H Y, Ma F Y. Cotton root morphology and dry matter accumulation at different film removal times. Agron J, 2017, 109: 2586–2597.
 Gerik T J, Morrison J E, Chichester F W. Effects of controlled traffic on soil physical properties and crop rooting. Agron J, 1987,79: 434–438.
 Pillinger C, Paveley N, Foulkes M J, Spink J. Explaining variation in the effects of take-all (Gaeumannomyces graminis var. tritici) on nitrogen and water uptake by winter wheat. Plant Pathol, 2005, 54: 491–501.
 Hoad S P, Russell G, Kettlewell P S, Belshaw M. Root system management in winter wheat: practices to increase water and nitrogen use. HGCA Project Report, 2004. p 351.
 Atta B M, Mahmood T, Trethowan R M. Relationship between root morphology and grain yield of wheat in north-western NSW, Australia. Aust J Crop Sci, 2013, 7: 2108–2115.