酥梨缺铁黄化症及矫治技术的研究

【作者】 张朝红；

【导师】 王跃进；

【作者基本信息】 西北农林科技大学 ， 果树学， 2000， 硕士

【摘要】 通过对酥梨缺铁黄化症的土壤分析、叶片分析来确定诱发黄化的主要因素。对不同程度黄化叶片的解剖结构、叶绿体色素和光合特性的分析为缺铁黄化诊断和矫治提供依据。在生长期采用自流式树干注射进行铁肥种类、浓度、注射液pH和多种药剂组合对缺铁黄化的防治试验。在休眠期，利用我们研制的黄叶绿（YLG）制剂进行防治黄化试验和为潜在性缺铁园补铁试验。YLG制剂作为一种注射专用肥进行施肥试验和注射施肥方式的研究，还对强力注射技术进行初步探讨，取得了以下研究结果： 1．通过对不同程度黄化树根际土和根丛土对比分析和不同程度黄化叶片分析，该区酥梨缺铁黄化的基本原因是土壤pH值高、有效铁含量低和根际土壤高P，直接诱因为土壤HCO₃^-含量过高，从而导致叶片高P和元素比例失调，叶片中铁失活，活性铁含量降低，出现叶片失绿黄化现象。 2．随失绿黄化程度的加大，叶片叶绿体色素的叶绿素a、叶绿素b、总叶绿素和类胡萝卜素均显著下降，叶绿素a与叶绿素b之比增大，叶绿素与类胡萝卜素之比变小，净光合速率下降，蒸腾速率变化不明显。 3．随缺铁黄化程度的加重，叶片厚度、叶肉厚度、叶片栅栏组织厚度、叶片栅栏组织与海绵组织之比均明显下降。海绵组织厚度变化不明显，细胞排列增密。栅栏组织细胞变短增粗，甚至断裂成块状，细胞层数减少，叶绿体数量减少，严重者甚至无叶绿体，维管束鞘和韧皮部细胞番红染色加重。 4．在生长季的矫治中，试验的5种含铁化合物复绿效果相近，注射液pH值对复绿影响不明显。在试验注铁量内，随注铁量的增加复绿效果越好，叶片叶绿体各色素增多，叶绿素与类胡萝卜素之比增大，叶片活性铁含量明显提高。在试验的药剂组合中，我们得到二个较好的防治药剂组合。 5．我们研制的YLG制剂在休眠期强力注射后，黄化园的黄化株率、黄化指数明显下降。叶片比叶重、单叶面积、叶绿素含量和挣光合速率增大，叶片解剖结构趋于正常。叶片N、P、Fe、Zn和活性铁增加，K、Mg、Mn、Cu、Ca含量下降，元素间比例趋于平衡，叶片表现正常；另一方面，注射YLG后，果实单果重增加，产量提高，含糖量增加，果实内在品质提高，在对当年发挥作用的同时，还增加花芽分化率和花芽质量，为翌年丰产奠定基础。对潜在性缺铁果园使用YLG后，效果基本同黄化园，也明显提高果实产量和品质。 6．在不同施肥方式中，注射＋土施和注射施肥的两种方式比传统土施＋叶喷的施肥方式的单叶面积、比叶重、叶绿素含量、净光合速率均有提高，叶片内营养元素N、P、Fb、Zn和活性Pe栅增加，单果重和产量闰显提高，果实品质以注射＋土施的施肥方式最好，注射施肥方式与传统土施＋叶喷果实品质相当，含有注射的两种施肥方式的成花率和花芽质量也明显提高，生产成本大大降低。在一定条件下可单独施用YLG制剂，一般在注射YLG后进行一定量的追肥，可提高生产效益。 7．强力注射后药液主要分布在树干和主根木质部中央，分枝后向各枝（根）均匀分配。注射孔在酥梨上不经处理当年基本可愈合。更多还原

【Abstract】 Major factors of the pear iron chlorosis were determined through soil testing and leaf analysis. The result of the leaf anotomical structure, the chloroplast pigment contents and the photosynthetic characteristics can provide diagnosis and correction of the iron deficency, according to the degree of chlorotic leaf The regreening effect of iron compounds, concentration, pH value and mixture more compounds were studied with the atuofiowing imjection in its growth period. Yellowing Leaf Green (YLG) ,our new-developed product for correcting the iron chlorosis, was applied to correct the iron deficiency in the iron deficiency oxchard and the potential iron deficiency oxchard. Injection fertilizing pattern and YLG injection fertilizer were evaluated and the technique of pressure trunk injection was studied. The results are as follows: 1. By means of analysis the rhizo sphere, the root zone soil and the leaves according to the degree of chlorotic tree or leaf, the basic reason of chlorotic disorder were high pH value of soil, low available iron and high rhizosphere phosphorus. The high HCO; content was the immediate reason of iron chlorosis. This soil conducted the pear leaf had high phosphorus elements in-ordinated and the iron inactive, so the active iron content reduced and pear leaves turned yellowish. 2. The content of leaf chlorophyll a, chl. b, total chl. And carotinoid reduced, chl. a/chl. b increased, total chl. /cartinoid reduced, net photosynthetic rate reduced, transpiration rate varied negligible, with the degree of pear leaf iron deficiency reducing. 3. With the methed of the wax section, the iron deficiency reduced the thickness of leaf, mesophylL, palisad tissue. palisad tissue/spongy tissue became small in the chlorotic leaf. The spongy tissue thickness had no obvious change. And it’s cell arranged densely. The palisad cell arranged loosely, became shorter and deformed lump. The amount of chloroplst reduced obviously. The vascular bundle sheat and the phloem were colored more red. The leaves of the injected iron tree regained normal structure. 4. Correcting trial during growthing season, the regre ing efficiency of five iron compound differed negligibly, and pH value of injected fertilizer did not effect the regreening efficiency. The bigger the iron amount of the treatment tree injected, the better the leaves regreened, the more the chlorophyll content was, the higher the iron and active content were. The trial gained two fomula of correcting iron deficiensis. The trial gained two fomula of correcting iron deficiency. 5. After applying the YLG injection fertilizer to the iron deficiency oxchard in dormancy period, chlorotic tree rate and chlorosis index decreased obviously. The individual leaf area, leaf area/leaf dry weight ratio, the content of chloroplast pigment, net photosynthesis rate increased. The amatomical structure of chlorosis leaf was normal. N~ P~. Fe~. Zn and active Fe contents in the leaves increased, and the others decreased. These result balance of elements in leaf. Through applycing YLG, the fruit yield increased obviously and the fruit quality improved, floral buddifferentiation rate and quality increased too. The potential iron deficiency tree was as same effect applying YLG injection fertilizer as the iron deficiency trees, and improved yield and quality. 6. The two pattern of injecting YLG raise the individual leaf area, the leaf area/leaf dry weight ratio, the chloroplast pigment and the net photosythesis rate compared the traditional soil更多还原