【Objective】Cold acclimation is an important physiological process for plants to increase cold resistance. The individual impact on the grape cold resistance from gene heredity and cultivation practice is quite stable, while the cold resistance of grape gained from cold acclimation in winter chang-es as the weather condition naturally varies with different years or places. Study on the responsive pro-cess of natural grape cold acclimation to low temperature and photoperiod is of great significance to re-veal the formation process and physiological mechanism of grape cold resistance. It needs to build the relationship model between the cold resistance of grape and low temperature in order to analyze the low temperature indices for cold acclimation of grape.【Methods】In this paper, the annual ripe grape canes of Cabernet Sauvignon and Beihong at the eastern foot of Helan Mountain were taken and used as testmaterials to measure the physiological and biochemical response indicators, such as supercooling point, freezing point, soluble sugar, soluble protein, conductivity, Ca2+, sucrose, ABA, etc. Thereafter, the ef-fect of natural cold acclimation on grape cold resistance was quantitatively evaluated by analyzing the response process of physiological and biochemical parameters to low temperature with the methods of variance analysis, t test and numerical simulation. The supercooling point and the freezing point were measured in the experimental frost box of SDX-20, in which the temperature sensors were fixed on the canes and data were taken once every 10 seconds. The supercooling point and the freezing point were determined according to the heat releasing process of tested canes. The dropping process of temperature was set as referring to the natural process with a decreasing rate of 3.0℃· h-1 from the room tempera-ture to-25℃. Conductivity was measured with DDSJ-308F conductivity meter firstly and then it was put in the boiling water for 30 minutes after it was sealed with glass stopper. After it cooled down to room temperature, the conductivity was measure again under the condition where it kept still after it was shaken slightly. The water content in canes was measured with the heating and weighing method. Ca2+ content was measured by following the microwave digestion method. Cane sucrose content was measured with the method of resorcinol colorimetry. The ABA concentration was measured with ABA test toolkit.【Results】The results showed that:(1) The lowest temperature was the dominant factor in the cold acclimation process;Under the low temperature condition, grapes could reduce the water con-tent in canes, increase Ca2+content, and improve the osmotic regulation ability of the canes;Under the low temperature condition, grapes could also improve the cold resistance by increasing the sucrose con-tent in canes. There was a significantly positive correlation between ABA content in canes and sunlight duration (photoperiod), but not closely related to the low temperature. Precipitation (irrigation) also played a significant role in the cold resistance of grape canes so that it reduced cold resistance of grape canes. (2) The indictor of cold resistance, which was calculated from the absolute difference value of maximum and minimum supercooling point values, showed that the cold resistance of Beihong canes was stronger than that of Cabernet Sauvignon. However, there was no significant difference in cold re-sistance for the physiological indicators between Cabernet Sauvignon and Beihong varieties in the same year, like supercooling points, conductivity and cane water content. There were significant differences in the supercooling point and the conductivity of Cabernet Sauvignon between different years, and there was a significant difference in the supercooling point of Beihong but there were no significant differenc-es for other indicators, like conductivity and cane water content. (3) The grape cold acclimation was gradually accumulated, and the grape cold resistance increased as the cold acclimation temperature dropped. There was a typical nonlinear logistic relationship between the grape cold resistance and the low temperature. When the temperature was lower than 18.0℃, grapes triggered the cold acclimation process. The cold resistance increased with the decrease of temperature. When the temperature was low-er than 12.0 ℃, the grape cold resistance increased rapidly. When the temperature was lower than 3.0 ℃, the increase of the cold resistance of grape canes slowed down, and the grape cold resistance reached the strongest before grapes were buried in the soil.【Conclusion】It was very complex physio-logical process of cold acclimation of grape as the intensity of cold acclimation was determined jointly by indicators, like grape gene heredity, photoperiod, low temperature, precipitation or irrigation and oth-er environmental factors. The low temperature was a major determinate factor in the cold acclimation of grape. With the decrease of temperature at the beginning of autumn, the cold resistance of grape canes increased logistically rather than linearly and this process was evolving gradually and cumulatively. Sunshine was the secondary factor to play a role in the process of grape cold acclimation by inducing ABA generation. It seemed that temperature and sunshine independently played roles in the process of grape cold acclimation.

Wine grape cannot grow well in cold areas. The cold resistance abilities of grape have become a very important problem to be solved. Effects of different fruit loads on the physiological and biochemical indexes of wine grape cultivar were studied through experiments. Results showed that different fruit loads had significant effects on the conductivity, soluble sugar content, Malondialdehyde (MDA), superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT) of grape branches. Factor analysis and principal component analysis were used to analyze the physiological and biochemical indexes of cold resistance of wine grapes with different loads. Results showed that combined with the physical microstructure, physiological and biochemical data of branches, the best fruit load of wine grape was 5 kg in eastern foot of Helan Mountain, China. Bangladesh J. Bot. 51(2): 263-270, 2022 (June)

贺兰山东麓地区受季风和大陆性气候影响,冬季寒冷干燥,低温持续时间长,酿酒葡萄越冬冻害频繁发生,严重制约葡萄与葡萄酒产业的可持续发展.文中对贺兰山东麓产区主栽的4个酿酒葡萄品种枝条进行抗寒性鉴定,旨在对酿酒葡萄抗寒育种、优良品种推广提供理论依据.文中以'北红''威代尔''西拉''赤霞珠'一年生枝条为试验材料,以4℃下保存的样本为对照,模拟自然冷冻降温过程,设置-10℃、-15℃、-20℃、-25℃、-30℃五个低温处理梯度,对各处理中枝条的保护酶活性、MDA、可溶性糖、可溶性蛋白、枝条萌芽率以及相对电导率、LT50进行测定及计算,运用相关性分析与隶属函数法对不同品种酿酒葡萄抗寒性进行综合评价.结果 表明:'北红''威代尔''赤霞珠''西拉'4种酿酒葡萄枝条半致死温度分别为-29.57℃、-27.26℃、-23.99℃、-14.10℃.相关分析结果表明,相对电导率、CAT活性、MDA、可溶性糖、可溶性蛋白含量与抗寒性呈负相关关系,枝条萌芽率、SOD、POD活性与抗寒性呈正相关关系.恢复生长法、LT50可作为判断酿酒葡萄枝条抗寒性强弱的单项指标.4种酿酒葡萄枝条抗寒性强弱顺序为'北红''威代尔''赤霞珠''西拉'.

葡萄越冬冻害是制约葡萄产业发展的障碍性因素之一,近年来国内外的研究表明,不同葡萄品种抗寒性差异很大,砧木嫁接可显著改善葡萄抗寒性;葡萄不同部位的抗寒力有明显差别,表现为枝条>芽眼>根系;低湿度日数与葡萄枝条死亡率的相关性最大,受冻后失水是树体死亡的直接原因;最主要的越冬防寒方式是埋土,研究者对不埋土越冬做了很多技术探索;通过可溶性糖、可溶性蛋白、组织含水量、相对电导率等指标可衡量葡萄枝条和根系的抗寒力.通过品种选育提高葡萄抗寒性、通过沟栽等栽培技术的改进保护根系免受冻害、通过选择保温又保湿的特殊材料覆盖是预防葡萄越冬冻害的有效途径.

[目的]研究‘马瑟兰’葡萄在不同采收期果实成分的变化,探索该品种在宁夏贺兰山东麓产区的最佳采收期.[方法]测定葡萄浆果的可溶性糖含量、可滴定酸含量、pH、可溶性固形物含量、总酚、单宁及花青素含量,运用聚类分析法和主成分分析法对葡萄浆果成分指标进行综合评价,以确定宁夏贺兰山东麓地区‘马瑟兰’葡萄的最佳采收期.[结果]2018年度宁夏贺兰山东麓产区‘马瑟兰’葡萄在9月10日至9月20日之间得分函数的分值大于零,其中9月13日的得分函数分值为最大值,达到了2.173.通过测定上述指标,结合聚类分析和主成分分析,可以实现对酿酒葡萄采收期较为客观、全面的判断.[结论]2018年度‘马瑟兰’葡萄的适宜采收时间段为9月10日至9月20日,其中9月13日为该地区‘马瑟兰’葡萄的最佳采收期.

越冬冻害是中国北方地区的主要气象灾害之一,严重影响着西北内陆埋土防寒区酿酒葡萄产业的可持续发展.葡萄不同部位抗寒能力具有差异,主要受品种遗传性状差异及各部位特性影响.本文基于差热分析技术对不同品种酿酒葡萄不同部位抗寒性进行测定,为葡萄越冬冻害的防御工作提供理论依据.本研究以贺兰山东麓主栽的4种酿酒葡萄'赤霞珠''美乐''西拉'和'北玫'的主根、副根和枝条为试材,在模拟自然降温冷冻过程中测定其过冷却点、结冰点、相对电导率和枝条含水率,并应用模糊隶属函数法综合评价4个品种酿酒葡萄根系的抗寒能力.研究结果表明:1)不同品种间的抗寒能力有显著差异,且不同品种根系、枝条抗寒能力趋势表现较为一致,4个品种抗寒能力大小顺序为:'北玫'>'赤霞珠'>'美乐'>'西拉'.2)半致死温度与根系过冷却点呈显著性相关,结合半致死温度确定供试品种根系的过冷却点温度范围为-5.2～-2.7℃,可作为4个酿酒葡萄品种根系越冬冻害的温度参考指标.供试品种各部位中枝条抗寒能力最强,主根次之,副根最弱,且主根抗寒能力显著大于副根.研究结果对于酿酒葡萄越冬冻害监测、预警和防御能力具有重要意义,也为酿酒葡萄抗寒性育种、优良品种的推广应用提供理论参考.

Jiangsu Province is one of major wheat-producing areas in China. In this region, winter wheat is often vulnerable to waterlogging stress in spring because of the cloudy and rainy weather. Moreover, the growth of winter wheat can be threatened simultaneously by inadequate sunlight. Waterlogging and inadequate sunlight have been thought to be common agricultural meteorological disasters in Jiangsu Province. However, little is known about the impact of the combined waterlogging and shading stress on the growth of winter wheat and the underlying mechanisms. Therefore, the aim of this work was to investigate the impacts of shading, waterlogging and combined stress on the photosynthetic ability and yield performance of winter wheat at the booting, flowering and grain-filling stages. The results showed that the photosynthetic ability of winter wheat was significantly influenced after treatment with shading, waterlogging and combined stress, and the impacts became more severe with the prolonged treatment. In terms of yield components, shading and waterlogging had the greatest impact on grain yield, followed by 1000-grain weight and grain number per spike. In conclusion, waterlogging and combined stress had more severe impact on the 1000-grain weight of winter wheat. The flowering and grain-filling stages were the sensitive stages at which winter wheat responded to shading and waterlogging. This study will be of great significance to enhance our understanding of the impact of shading and waterlogging on the growth of winter wheat and find ways to improve stress tolerance of winter wheat to adverse weather condition to further increase grain yield. (C) 2019 Friends Science Publishers

为了充分发挥土壤水分自动观测数据在气象业务和科研工作中的作用,本研究以山东省为例,研究了土壤水分的时空分布规律,并利用K聚类分析方法进行了分区研究.结果 表明2016年山东省不同层次土壤的水分含量呈现出东部半岛低于中、西部的规律;表层的土壤水分含量较低,且土壤含水量的空间差异小于深层.海阳和章丘2个典型站点表层土壤水分的波动较下层更明显;气温、相对湿度、气压、降水和土壤温度等气象因子在不同层次上对土壤水分含量有明显的影响.利用K聚类分析方法结合站点的空间分布情况,可以将山东省分为4个区域,并在东西方向上依次分布.