【作者】 沈宝云；

【导师】 王蒂；

【作者基本信息】 甘肃农业大学 ， 作物遗传育种， 2013， 博士

【摘要】 马铃薯（Solanum tuberosum L.）是仅次于水稻、小麦、玉米的世界第四大作物。中国是世界马铃薯生产大国，种植面积和总产量均位居世界第一位。马铃薯产业发展存在一些问题，如干旱缺水和连作逆境导致产量和品质下降、专用品种的育种效率低下、贮藏生理研究不足导致烂窖率较高等等，其中连作障碍问题目前已成为影响我国马铃薯主产区生产的重要制约因素之一。本研究选择西北乃至全国主栽的马铃薯优良品种，进行连作逆境下马铃薯形态特征、生理特性及产品质量的评价和研究，明确连作抗性品种及敏感性品种，分析根系分泌有机物的类型和含量，解析酚酸类化感物质对马铃薯植株生长发育影响的机理，探究钙信号分子对连作马铃薯抗性变化的作用，评价有机肥与生物菌肥混合对连作障碍缓解的效应，为西北干旱区连作逆境下马铃薯生产及农田生态系统健康和可持续性发展提供理论依据。取得的主要研究结果如下：1、连作6年田中，马铃薯8个品种的株高较正茬田明显下降，苗期降幅最大（46.57%）、现蕾期降幅最小（28.69%），且连作对植株茎的横向生长的影响小于纵向生长；8个品种中，‘大西洋’株高受连作逆境的影响最小，表现为4个发育时期株高平均降幅为21.22%，‘费乌瑞它’受到的影响最大（44.45%）；连作6年地块中，8个品种均严重减产，减幅达78.14%～97.84%，其中低产品种‘费乌瑞它’减产幅度最大（97.84%），高产品种‘青薯2号’减产幅度最小（78.14%），且显著低于其它品种，但结合商品薯率指标发现，‘青薯2号’薯块商品薯率较低，其基本失去了经济效益，故在总产一定量的前提下，商品薯率为更为重要的评价指标；综合评价认为，高连作田块中，‘大西洋’为较好的抗连作品种。且连作6年田对马铃薯产量影响十分严重，‘费乌瑞它’品种单位面积上产量大幅降低，甚至绝收。因此，连作6年田已失去种植马铃薯的能力。2、连作5年田中，5个品种的株高变化均呈现随植株发育进程的延长，受抑制程度加剧，降幅最大品种是‘夏波蒂’（33.17%）和‘克新1号’（31.69%）；根总长、根表面积和根体积较对照也均呈下降趋势；结合株高、根变化（总长、表面积、体积）及产量和商品薯率分析，确定‘克新1号’为连作敏感型品种。3、与轮作地块相比，连作1年和2年马铃薯产量无显著变化，连作3年后出现显著下降，降幅达44%～56%，说明连作两年后应是当地‘大西洋’品种连作的最佳终止时间；连作马铃薯植株的光合生理受影响显著，其中Pn、Gs和Tr随连作年限的延长显著下降，Ci则表现上升趋势，叶绿体荧光特征则表现为F0随连作年限的延长而逐渐下降，Fv/Fm、ΦPSII和qP逐渐上升；叶片SOD、POD和CAT活性表现出随连作年限的延长先上升后下降的特征，与不连作相比，连作1年和2年叶片的MDA含量无显著变化，但连作3～5年增加了4～6倍；随连作年限延长，根系活力和总吸收面积及活跃吸收面积显著下降。结果初步表明，马铃薯连作障碍产生的原因是植株光合生理及抗氧化生理系统发生了改变，导致植株形态特性随之改变，加之根系生理活力和吸收面积的显著下降，直接导致其对根-土界面养分物质和水分的吸收能力降低，从而影响了块茎产量的形成和地上部植株的正常生长和发育，最终导致马铃薯连作障碍产生。4、马铃薯在出苗期和落花期分别提取连作3年和轮作（前3年均为玉米）的马铃薯根际土壤溶液进行GC-MS分析，对匹配度80%以上的40多种有机物进行连作和轮作的比对分析。发现出苗期连作3年土壤中，壬C9H20、N，N-二甲基甲酰胺、2-辛烯醛、辛醛、十一烷、乙酸-2-乙基己基酯、2-十一烯醛、1-十二烯、1-十三烷醇、1-十五碳烯、二丁基羟基甲苯、1,2-苯二甲酸二（2-甲基丙基）酯、5-十八烯14种化合物为连作根际土壤中所存在的物质。但与落花期连作和轮作土壤的化合物比对分析后发现，除N，N-二甲基甲酰胺外，其他物质落花期在两种根际土壤溶液中均存在，故初步认为它们均不是化感自毒物质，但N，N-二甲基甲酰胺的作用尚需进一步研究。落花期又发现10种独有的化合物（甲酰胺-N，N-二甲基、醛、正辛烷-3-乙基、1-十六碳烯、8-十七碳烯、十六烷酸丙基酯、二十烷、3,3-二甲基-辛烷），其中十六烷酸丙基酯也称棕榈酸丙基酯，是已知的植物自毒物质，但其在马铃薯中的作用尚待进一步验证，其他9种化合物的作用也需进一步分析。5、由于对羟基苯甲酸、香草酸和阿魏酸是连作土壤中3种重要的化感自毒物质，通过分别浇灌这三种酚酸溶液及其混合液发现其对马铃薯植株的株高、茎粗、地上分茎数、匍匐茎数和根长皆有显著抑制作用，且混合酚酸溶液的抑制效果大于相同浓度的这三种酚酸中任一溶液；上述酚酸物质还显著抑制了马铃薯植株的根系活力和叶绿素含量，减低了叶片净光合速率，而且上述作用随酚酸溶液浓度增加而显著增加，这些影响对马铃薯植株的生长发育可能具有直接且重要的作用。外源酚酸还显著提高了叶片MDA含量，并对应着抗氧化酶活性的整体下降，这一效果随着外源酚酸溶液浓度的增加而加强，并以混合酚酸的效果最为显著。6、叶面喷施氯化钙可显著减轻连作对马铃薯幼苗生长发育的抑制，提高马铃薯块茎淀粉、维生素C和可溶性蛋白的含量，提高块茎硬度及单株产量；氯化钙处理还显著减小了连作引起的叶片叶绿素、脯氨酸和可溶性糖含量下降的幅度，提高了SOD和CAT活性，同时降低MDA含量和活性氧水平。表明叶面喷施氯化钙可显著提高马铃薯植株对连作逆境的整体抗性，减轻连作所造成的生理障碍，促进连作马铃薯植株的生长发育，并改善马铃薯块茎营养和产量。7、马铃薯连作田在常规施肥的基础上增加有机肥、腐殖酸铵复合肥和微生物肥的混合有机肥，无论是产量还是经济效益均优于仅常规施肥，且混合有机肥的不同施用量对轮作和连作下的马铃薯产量和经济效益有不同影响，其中有机肥、腐殖酸铵、微生物肥的施用量分别为800㎏/667m2、75㎏/667m2、5㎏/667m2时，轮作和连作田的马铃薯产量和经济效益均最高。更多还原

【Abstract】 Follow the rice, wheat and maize, potato (Solanum tuberosum L.) is the fourth-mostimportant food crop worldwide. It is one of the major crops in China as well. To date, theplanting acreage and production of potato in China ranked as top one worldwide. However,the shortage of the irrigation water and the continuous cropping significantly impacted theyield, quality, commercialization rate and the storage life of the potato tuber in China. Thecontinuous cropping currently is the main factor that affect the potato production in thepotato growing. In this study, the morphological, physiological characteristics and the tuberquality under the continuous cropping were analyzed. The genotypes that showed resistanceagainst the continuous cropping were characterized. The composition and characteristics ofthe root secretion were analyzed. The impact of phenolic acids on the growth of potato wasdiscussed. The effects of Ca signaling on the resistanse of potato to the continuous croppingwere also analyzed. The effects of organic fertilizer and biological fertilizer on easingcontinuous cropping stress were evaluated. The outcomes of this study should provide thetheoretical foundation for the sustainable development of the potato production as well asthe farming land ecological system in arid land of Northwest Continuous Cropping Region.The main conclusions were summarized as follow:1、In the field of6years continuous cropping, the plant height of8varieties wassignificantly lower than those from non-continuous cropping field. The maximumdifference was observed during the seeding stage, while the minimum difference showedduring the squaring stage. The continuous cropping affected the longitudinal developmentof the tuber. Among8varieties, the plant height of Atlantic is the least affected, the averagedecrease of the height during the4growth stage is21.22%. Favorita is the most affected(44.45%). All tested varieties showed significant yield reduction in the6year continuouscropping field, the reduction is ranged from78.14%(Qingshu-9)-to97.84%(Favorita). Thecommercialization rate of Qiangshu-9is extremely low, suggesting that the harvested tuberdid not have any economic value. The commercialization rate usually is one of theimportant evaluation indexes when the yield is fixed. Therefore, the results indicated thatAtlantic is relatively resistant to the continuous cropping, six years continuous croppingseverely reduced the yield of potato, the harvest index of unit area was significantly declined. As conclusion, the6years continuous cropping land is not suitable for growingpotato.2、In the5years continuous cropping field, the plant height of5varieties wasgradually reduced with the development of the plant. The plant height of shepody andKexin-1was decreased33.17%and31.69%, respectively. The root length, root surface areaand root volume showed slightly reduction when compared with those from the controlfield. The physiological data combined with the commercialization rate index indicated thatKexin-1is sensitive to the continuous cropping.3、When compared to the rotation field, one or two years continuous cropping did notaffect the yield of potato. After3years continuous cropping, the yield reduced to44-56%.The results suggested that Atlantic should not be continuous cropped more than2years.The photosynthetic activities of potato plant was significantly affected by the continuouscropping. Pn、Gsand Trwere declined with the increasing of continuous years, Ciwasincreased. F0of chlorophyll fluorescence were declined with the increasing of continuousyears，Fv/Fm、ΦPSIIand qP were increased. SOD, POD and CAT of leaves showed increasingat early years and decreased with the increasing of continuous years. When compared withthe non-continuous cropping, the MDA content of leave did not affected by1or2yearscontinuous cropping, but increased4-6folds when continuous cropping last3-5years. Theroot activities, total absorption surface and active absorption area were significantlyreduced with the increasing of continuous year. The results thus suggested that the potatocontinuous cropping obstacle was caused by the variation of photosynthetic and antioxidantsystems, the change of the morphological characteristics of the plant, the reduction of rootphysiological activities and absorption area. as a results, the absorption ability of root touptake nutrient and water from the root-soil interface was reduced, and therefore the growthof tuber and dry matter accumulation in tuber were also affected. The yield formation oftuber and the normal growth of above ground part of plant were further affected, and thepotato continuous cropping obstacle was formed as a result.4、The soil solutions from3year continuous cropping field and rotation field duringthe seedling and the falling flower stage were against the GC-MS analysis, a total of40organic chemicals were analyzed for both continuous cropping and rotation. During theseedling stage, about14organic chemicals were detected in the soil of the continuous cropping field: Pelargonic C9H20, N, n-dimethyl formamide,2-octenal, octenal, undecane,Acetic acid-ethyl-Hexyl ester,2-11allyl aldehyde,1-dodecene,1–13OL,1-15-Ene, dibutylhydroxy toluene,1,2-acid22-methylpropyl ester,5-18Ene. During falling flower stage, allorganic chemcials except N, n-dimethyl formamide were detected in both continuouscropping and rotation field soil solution, suggesting that N, n-dimethyl formamide is theautointoxication of allelopathic substance, but the inhibition activities of N, n-dimethylformamide need to be studied in the future. About10more chemicals were detected duringthe falling flower stage, Formamide-n, N-dimethyl, aldehyde, Are octan-ethyl, cetene,8-17Ene,16acid propyl ester, eicosane, octane,3-3Dimethyl. hexadecanoic acid also calledpalmitinic acid, it is a known autointoxication substance. The roles of hexadecanoic acidand other nine chemicals in affecting potato growth need to be studied in the future.5、Para-hydroxybenzoic acid, vanillic acid and ferulic acid are three importantautointoxication of allelopathic substances. Application of these three solution and mixtureon the potato plant showed inhibition effects on plant height, stem diameter, above groundstem numbers, creeping stem numbers and root length. The mixture that include all threechemical showed greater effects than individual application. The root activity andchloroplast content of potato also affected by the chemicals, the net photosynthetic rate wasdeclined as a result. The inhibition activities were enhanced with the increasedconcentration of solution. Those effects might directly involved in the development ofpotato plants. With the addition of phenol acid, especially the mixture of three chemicals,the MDA content of leaves were increased and the activities of antioxidant enzymes weredecreased.6、The direct spraying of CaCl2on the leaves can significantly ease the inhibitionactivities of the continuous cropping on the potato seedlings. The starch content, vitamin C,soluable protein content, hardness of tuber, and tubers per plant were also increased whenCaCl2was sprayed. The continuous cropping caused the reduction on chloroplast content,while proline and soluble sugar content were significantly restored. The SOD and CATactivities were increased, the MDA content and the active oxygen were declined. Theresults indicated that the spraying of CaCl2could significantly increase the continuouscropping resistance of potato plant, ease the physiological obstacle caused by continuouscropping, benefit the growth of the potato plant, as a result improve the nutrient and yield of tubers.7、Addition of mixture fertilizer includes organic fertilizer, ammonium humic acid,compound fertilizer and microbal fertilizer showed significant effects on the yield and theeconomical value of tuber. The optimized mixture of organic fertilizer, ammonium humicacid compound fertilizer and microbal fertilizer is800kg/667m2、75kg/667m2、5kg/667m2,respectively.更多还原