摘要
【目的】探究琯溪蜜柚叶片黄化与营养元素丰缺的关系并进行矫正,为生产上制定合理施肥措施提供科学依据。【方法】采集了38个有代表性的琯溪蜜柚果园的不同黄化程度的叶片,研究5个黄化等级(等级为0、1、2、3和4,分别对应对照绿叶、约25%、50%、75%和100%黄化面积)的蜜柚叶片的SPAD值和营养元素浓度的变化;并进一步研究叶面补镁(叶面喷施2%七水硫酸镁)对蜜柚叶片黄化的矫治效果。【结果】随着黄化等级的增加,蜜柚叶片的SPAD值显著降低。蜜柚叶片氮浓度、磷浓度、钙浓度和硼浓度随着叶片黄化程度加剧而降低,其中黄化等级为3~4时的叶片氮浓度低于适宜范围,而不同黄化等级的叶片磷浓度、钙浓度和硼浓度均处于适宜范围(除了黄化等级为4时的叶片硼浓度低于适宜范围)。随着黄化等级的增加,蜜柚叶片的镁浓度随之显著降低,黄化等级为1时的叶片镁浓度较对照绿叶降低了44%,而且黄化等级为1~4的叶片镁浓度均低于适宜范围。相反,蜜柚叶片的钾浓度、铁浓度和锰浓度随着黄化等级的增加而提高,但是不同黄化等级之间的铜浓度和锌浓度均差异不显著,同时叶片的锌浓度有低于适宜范围风险。相关性分析可知,蜜柚叶片的SPAD值与叶片镁浓度(r=0.819)、氮浓度(r=0.763)、磷浓度(r=0.600)、钙浓度(r=0.476)和硼浓度(r=0.378)显著正相关,而与钾浓度(r=-0.570)、铁浓度(r=-0.495)和锰浓度(r=-0.198)显著负相关。通径分析和随机森林分析表明镁对蜜柚叶片SPAD值影响最大,其次是氮和钾。叶面喷施硫酸镁后蜜柚叶片的镁浓度和SPAD值显著提高,而叶片的钾浓度显著降低。【结论】蜜柚叶片黄化主要与缺镁有关,叶面补镁可以改善蜜柚叶片营养,缓解叶片黄化症状。
【Objective】Guanximiyou pomelo(Citrus grandis)is an important and popular Citrus species,and Pinghe county in Fujian province is the main Guanximiyou pomelo production region in China.Leaf yellowing could decrease photosynthetic physiology and products,resulting in the yield reduction and quality deterioration.In the recent years,leaf yellowing has become widespread phenomenon in Guanximiyou pomelo orchards of Pinghe county.However,whether the yellowing of pomelo leaves is caused by magnesium(Mg)deficiency,insufficient information has been reported.Thereby,it is important to reveal the relationship between leaf yellowing and corresponding nutrient elements concentrations(especially Mg concentration)in Guanximiyou pomelo,and the effect of foliar Mg supplement on pomelo leaf yellowing.【Methods】Leaves of Guanximiyou pomelo with different yellowing degrees from 38 orchards were collected and divided into five grade levels including green leaf(control),about 25%,50%,75% and 100% leaf yellowing area.We also studied the effect of foliar Mg supplement(foliar spraying with 2% magnesium sulfate heptahydrate)on SPAD value,Mg,N and K concentrations in pomelo leaves.The control(CK)was foliar spraying with water.The spraying amount was 7 L per plant and the spraying time was April,May and June.The leaves on spring-growing shoots from the previous year wood were collected at the mature stage.Leaf SPAD value with five yellowing grades were determined by the SPAD-502 chlorophyll meter.Leaf samples were digested with H2SO4–H2O2,then nitrogen(N)concentrations were measured using flowage analyzer,phosphorus(P)concentrations were measured using inductively coupled plasma optical emission spectrometer,and the concentrations of potassium(K)were determined using flame photometer.The calcium(Ca),magnesium(Mg),iron(Fe),Boron(B),manganese(Mn),copper(Cu)and zinc(Zn)concentrations of samples were digested using HNO3-HClO4 and analyzed by the inductively coupled plasma optical emission spectrometer.【Results】Our results showed tha
作者
张炎
曹振
周慧梅
沈海芹
苏达
吴良泉
叶德练
ZHANG Yan;CAO Zhen;ZHOU Huimei;SHEN Haiqin;SU Da;WU Liangquan;YE Delian(College of Resources and Environmental Sciences/International Magnesium Institute,Fujian Agriculture and Forestry University,Fuzhou 350002,Fujian,China;College of Agriculture/Key Laboratory of Ministry of Education for Genetics,Breeding and Multiple Utilization of Crops,Fujian Agriculture and Forestry University,Fuzhou 350002,Fujian,China)
出处
《果树学报》
CAS
CSCD
北大核心
2021年第8期1319-1329,共11页
Journal of Fruit Science
基金
国家自然科学基金(31701367)
福建省自然科学基金(2020J01534)
国际镁营养研究所开放基金(IMI2018-11)。
关键词
蜜柚
叶片黄化
缺镁
叶面镁肥
Pomelo
Leaf yellowing
Magnesium deficiency
Foliar magnesium fertilizer
