Chin J Plan Ecolo ›› 2011, Vol. 35 ›› Issue (3): 284-293.doi: 10.3724/SP.J.1258.2011.00284

• Research Articles • Previous Articles     Next Articles

Density-dependent regulation of above- and below-ground modules in Allium cepa var. proliferum populations

LI Lei1, ZHOU Dao-Wei1,2*   

  1. 1State Environmental Protection Key Laboratory of Wetland Ecology and Vegetation Restoration, College of Urban and Environmental Sciences, NortheastNormal University, Changchun 130024, China;

    2Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun 130012, China
  • Received:2010-04-19 Revised:2011-01-07 Online:2011-03-02 Published:2011-03-01
  • Contact: ZHOU Dao-Wei E-mail:zhoudaowei@neigae.ac.cn

Abstract:

Aims Although the relationship between size and density is central to plant ecology, research has focused on the above-ground parts of plants and few studies have examined size-density relationships of below-ground modules. Density-dependent regulation in plants can be viewed not only at population and individual levels, but also at plant part level, since growth in plants is a modular process. Our aims were to (1) investigate size-density relationships at plant part level and at individual plant level for both below- and above-ground parts of plants and (2) compare size-density relationships at the levels of plant parts and individuals. Methods Allium cepa var. proliferum was planted in a completely random design at five plant densities (36, 49, 64, 121 and 225 plants·m–2) and three replicates. Plot size was 5 m × 5 m. At harvest time (July 11), ten plants from each plot were destructively sampled to measure plant height, number of leaves, length of leaf blade, bulb diameter and mean weight per tiller. Each plant was separated into root, bulb, sheath and leaf blade, oven-dried for 120 h at 80 ℃, and then weighed. Regression analysis was conducted to explore the relationship between the characters measured and plant density and the allometric relationships of mean masses of below- and above-ground modules with density at plant part level and individual level. Important findings Relationships between plant density and dry weight of root, bulb, leaf blade and sheath showed negative power functions with different allometric exponents for different plant modules: bulb (–1.14) < leaf blade (–1.03) < root (–0.78) < sheath (–0.49). Masses of below- and above-ground dry matter, as well as the whole plant, were decreased significantly with increased plant density. The allometric exponents were –1.13, –0.95 and –0.98 for below-ground, above-ground and individual plant dry matter, respectively. We concluded that the effect of density-dependent regulation on below-ground modules may be greater than that on above-ground modules. Blow-ground parts may be more closely constrained by plant density in contrast to above-ground parts and the whole plant. Consequently, competition for below-ground resources is predominant in the A. cepa var. proliferum populations.

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[1] Yang Ying-gen;Zhang Li-jun and Li yu. Studies on the Postharvest Physiology properties of Peach Fruits[J]. Chin Bull Bot, 1995, 12(04): 47 -49 .
[2] Zhou Shi-gong. Applications of Lanthanum in Botanical Research[J]. Chin Bull Bot, 1992, 9(02): 26 -29 .
[3] . [J]. Chin Bull Bot, 1996, 13(专辑): 105 .
[4] 杜维广 王彬如 谭克辉 郝迺斌. An Approach to the Breeding of Soybean with High Photosynthetic Efficiency[J]. Chin Bull Bot, 1984, 2(23): 7 -11 .
[5] ZHAO Yun-Yun ZHOU Xiao-Mei YANG Cai. Production of Hybrid F1 Between Avena magna and Avena nuda and It''s Identification[J]. Chin Bull Bot, 2003, 20(03): 302 -306 .
[6] . Professor Jiayang Li, a Plant Molecular Genetist[J]. Chin Bull Bot, 2003, 20(03): 370 -372 .
[7] . [J]. Chin Bull Bot, 1996, 13(专辑): 100 -101 .
[8] Qiong Jiang, Youning Wang, Lixiang Wang, Zhengxi Sun, Xia Li. Validation of Reference Genes for Quantitative RT-PCR Analysis in Soybean Root Tissue under Salt Stress[J]. Chin Bull Bot, 2015, 50(6): 754 -764 .
[9] MA Ke-Ming. Advances of the Study on Species Abundance Pattern[J]. Chin J Plan Ecolo, 2003, 27(3): 412 -426 .
[10] ZHANG Zhi-Meng, WAN Shu-Bo, NING Tang-Yuan, DAI Liang-Xiang. EFFECTS OF NITROGEN LEVEL ON NITROGEN METABOLISM AND CORRELATING ENZYME ACTIVITY IN PEANUT[J]. Chin J Plan Ecolo, 2008, 32(6): 1407 -1416 .