【作者】 孟庆瑞；

【导师】 杨建民；

【作者基本信息】 河北农业大学 ， 森林培育， 2009， 博士

【摘要】 杏(Prunus armeniaca Linn.)是蔷薇科(Rosaceae)杏属(Prunus Linn.)果树,杏树已成为农村经济的主要来源之一。在生产中,由于春季开花较早,晚霜危害十分严重,花期一旦遇到霜冻,轻者减产,重者绝收,故晚霜已成为制约仁用杏产业发展的限制因子。为系统深入的阐明杏树霜冻害机理,为生产上制定有效的防霜措施提供理论依据和探索新的防霜途径,本研究以不同杏品种为试材,开展了不同发育时期花器官过冷却点变化,低温胁迫下对花器官抗寒性、授粉特性的影响,综合栽培措施对花器官抗寒性的影响,及药剂防霜的研究,主要结果如下:1.杏花的抗寒性与其发育时期有关,表现为:随杏花发育进程的推移,5个杏品种自大蕾期至幼果期过冷却点、结冰点呈现明显上升趋势。幼果对霜冻最敏感,而盛花期是杏花器官最为敏感的时期;花器官中以花瓣过冷却点和结冰点最低,雄蕊次之,雌蕊最高,雄蕊、雌蕊过冷却点较花瓣高1℃～2℃;品种间抗寒性顺序为优一>龙王帽>红荷包>金太阳>凯特。2.低温胁迫对杏花器官抗氧化系统、渗透调节物质和激素含量产生的影响表现为:低温胁迫下,与对照相比,花器官O2.—产生速率、H2O2含量、膜脂过氧化产物MDA含量均呈现上升趋势,且均表现为花瓣>雄蕊>雌蕊;花器官抗氧化酶(SOD、GPX、CAT、APX、GR、DHAR、MDHAR)活性随温度呈现先上升后下降的趋势,但酶活性高低因花器官不同而异;抗氧化剂中除DHA含量随温度下降而下降外,花器官ASA、GSH、GSSG含量呈现先上升后下降的趋势,但不同器官达到最大值时的温度不同;另外,低温持续时间延长对花器官的伤害与温度下降的效果相似,即低温持续时间的延长亦会使花器官膜透性、MDA含量增加。花器官可溶性蛋白、可溶性糖、脯氨酸含量随胁迫温度下降呈现上升的趋势,但含量高低在花器官间差异较大,花瓣、雄蕊、雌蕊分别以脯氨酸、可溶性糖、可溶性蛋白质含量最高。激素与杏花器官抗寒性相关,表现为:不同激素类型随温度变化的趋势不同,且不同花器官间激素含量高低亦存在差异,IAA和ABA含量以花瓣中最高,而GA、Z+ZR含量则以雌蕊中最高,但花器官激素间的比值(ABA/GA、ABA/IAA、ABA/Z+ZR)均表现为花瓣>雄蕊>雌蕊。花器官中未检测到ZT。3.低温胁迫对杏授粉生物学特性的影响表现为:低温降低了花粉生活力、萌发率和花粉管长度,但低温胁迫对不同品种花粉生活力影响存在差异。对授粉后4h、24h分别进行-2℃、-3℃低温处理,恢复不同时间后进行花柱荧光显微镜观察表明,温度越低,对花粉管在花柱内生长的抑制越明显,且使花粉管停止生长的时间提前。而在不同发育时期授粉花柱中花粉管受低温影响程度不同,表现为低温对授粉后4h的花粉管伸长生长的影响较授粉后24h大。4.综合栽培措施对树体生长、土壤理化性质和花器官抗寒性的影响表现为:综合栽培措施分别促进龙王帽外围枝条增长、增粗30.50cm和0.52cm,提高了叶片光合效率、有效花比例和坐果率,并提高了杏仁的出仁率和品质;综合栽培措施改善了土壤理化性质,提高了土壤微生物数量,增强了蔗糖酶、蛋白酶等土壤酶活性,促进各土层须根显著增加,使须根数量在0-30㎝、30-60㎝、60-90㎝土层分别是对照的2.17、1.17、1.56倍;综合栽培措施降低了花器官过冷却点、相对电导率、MDA含量,显著提高了SOD、POD酶活性及可溶性蛋白和脯氨酸含量,使杏花器官抗寒性增强。5.采用vali结冻法和含菌平板培养法,从9种供试药剂中筛选出1号、2号、3号、5号、7号5种对INA细菌触杀及破坏冰蛋白作用的药剂。将5种筛选的药剂于日光温室和田间进行药剂防霜试验研究,结果表明,日光温室霜冻温度为-4℃时,5种药剂中3号、7号防霜效果显著,分别为47.05%~67.74%和49.44%~69.33%。3号、7号分别提高坐果率12.25%~14.83%和4.69%~11.36%,与对照相比差异达显著水平。大田温度为-6.5℃时,5种药剂中3号的防霜效果为21.80%,提高坐果率9.17%,与对照相比达显著水平。更多还原

【Abstract】 As a fruit tree in rose family (Rosaceae) and apricot genus (Prunus Linn.), apricot (Prunus armeniaca Linn.) has already been taken as one of the main resources for rural economy. Since blooming early in spring, it is often injured by late frost, and yield loss induced by frost at blooming period was 30%-40% almost every year, or sometimes there will be no production at all. Because of this quite serious loss, frost has already been one of the critical restricting factors in the cultivation and development of apricot. And this problem has not been resolved effectively. In order to clarify the mechanism of frost injury to apricot, to provide theory basis and probe new ways for effective frost provention,diferent apricot cultivars were used as materials to study the changses of supercooling points at different developmental stages, effects of low temperature on cold resisitence, pollination in floral organs, effects of comprehensive measures on cold resisitence in floral organs, and frost-controlling efficacy of bactericides. The main results of the sduty are as follows:1. The cold resisitentce of apriot flowers were in relationship with those development stages. The results showed that, with the development of flower buds, SCP and FP in five apricot cultivars increased. Young fruits were mostly sensitive to frost, while at blooming period floral organs were sensitive to frost; among three florlal organs, the lowest SCP and FP were in petal, then stamen and pistil. SCP in stamen and pistil were 1℃～2℃higher than that in petal; The order of cold resistence among cultivars was Youyi>Longwangmao>Honghebao>Golden sun>Katy.2. The effects of low temperature on antioxidant defence systems, osmolytes contents, and hormone contents were showed as follows:Compared with control, O2.—genaration rate H2O2 concentrations, MDA concentrations of apricot floral organs under different low temperatures were in increasing trends, and the order of floral organs in three index were all taken as petal>stamen>pitil; Activities of SOD, GPX, CAT, APX, GR, DHAR, MDHAR were in the trend of increasing firstly, and then decreasing, while different enzyme activities varied with floral organs, which indicated that different floral organs depented on different antioxidant enzymes to eliminate ROS for frost precention. Antioxidant concentrations were increased firstly and then decreased, but DHA concentration was excepted. The temperature at which antioxidant concentrations were the highest varied with floral organs. In addition, low temperature duration increased relative electrolytic leakage and MDA concentrations in floral organs of apricot, which indicated that the damage induced by low temperature and its duration was in similar to low temperatures.With temperature decreasing, soluble protein, soluble sugar and pro-aa contents of floral organs increased, while contents were different among floral organs, which maybe in relation to pollination beside saturation modulation.Hormone were in relation to cold resisitance of apricot floral organs, while hormone type varied with the changes of temperature, and hormone concentrations were difference among floral organs. Concentrations of IAA and ABA were the highest in petals, but GA and Z+ZR concentrations were the highest in pistils. The ratio of ABA/GA, ABA/IAA and ABA/Z+ZR were behaved as petal>stamen>pistil, which indicated that cold resisitance did not rest on a certain hormone, but the ratio among hormones. ZT was not examined in apricot floral organs.3. Low temperature affected pollination biology of apricot, the results showed that: low temperature decreased the pollen activity, pollen germination, and pollen tube length of apricot, but the effect of low temperature treatment on pollen activity of different cultivars was diversity. The stylars treated with -2℃or -3℃after pollination for 4h and 24h respectively were examed using fluorescence microscope, the results showed that low temperature restrained the development of pollen tube, and stopped those development in stylar forwardly, while the damage degree of low temperature to pollen tube in pollinated stylar varied with development period, it showed that the effect of low temperature on pollen germination 4h after pollination was significant than that 24h after pollination.4. The development of peripheral branches, soil properties and cold resisitence of floral organs were studied after using comprehensive cultural measures, the results showed that, comprehensive cultural measures promoted the peripheral branches 30.50cm longer and 0.52cm thicker than its controls, increased the photosynthetic rate of leaves, the ratio of effective flower, and fruit set percentage, and enhanced apriot kernel/fruit apriot and kernel quality. The comprehensive cultural measures improved soil properties, enhanced the amount of microorganism in soil, promoted activities of correlative enzymes,such as invertase,protease. This cultural measure caused fibres development by increasing the amount of fibres at layer of 0cm-30cm, 30cm-60cm, 60cm-90cm by 2.17, 1.17,1.56 times respectively, compered with control. In addition, Comprehensive cultural measures decreased SCP, cell membrane permeability significantly, and MDA concentrations of Longwangmao, improved activity of SOD and POD, concentrations of soluble protein and pro-aa significantly, decreased frost injury index of floral organs, thus cold resistance of apricot floral organs were improved. 5. Five out of nine bactericides,labeled as No.1, No.2, No.3, No.5, and No.7, were selected for eradicating INA bacteria and destroying ice-nucleation protein by means of vali and culture on medium containing INA bacteria. The effects of selected bactericides were investigated on preventing frost damage in solar greenhouse and field. The results indicated that when frost occurred at -4℃in solar greenhouse, both No.3 and No.7 were most effective among the five bactericides with frost-controlling efficacy being 47.05%~67.74% and 49.44%~69.33%, respectively, and No.3 and No.7 increased percentage of fruit set by 12.25%~14.83% and 4.69%~11.36%, respectively, as compared with control. In filed experiment, the frost-controlling efficacy of No.3 was 21.80% at -6.5℃, and it significantly decreased the percentage of fruit set by 9.17%.更多还原