【作者】 张舒涵；

【导师】 李朝周；

【作者基本信息】 甘肃农业大学 ， 植物生态生理学， 2018， 硕士

【摘要】 本试验以马铃薯品种“大西洋”为材料,于2016年至2017年在甘肃省景泰县条山农场（37°11’N,104°03’E）马铃薯试验基地,研究了干旱胁迫下增施钾肥、磷肥以及充分灌溉下不同氮肥基追比对马铃薯植株生长发育、根系生理和形态的影响。本试验主要结论如下:通过在轻度干旱胁迫、中度干旱胁迫和充分灌溉三个水分条件下,分别设置0、1.2、2.4、3.6、4.8、6.0（以单株K₂O记,单位g）6个钾肥增施水平和0、0.485、0.97、1.455、1.94、2.425（以单株P₂O₅记,单位g）6个磷肥增施水平,研究不同土壤水分条件和不同钾肥、磷肥增施量对马铃薯植株根系抗性生理、形态特征、生物量积累以及块茎产量的影响,结果表明:（1）随着土壤水分亏缺的加剧,马铃薯地上部生长和干物质积累皆受到不同程度的抑制,而不同干旱条件下增施适量磷、钾肥可通过提高马铃薯植株的根系含水量和根系活力、增强根系超氧化物歧化酶（SOD）、过氧化物酶（POD）和过氧化氢酶（CAT）活性来缓解干旱胁迫下马铃薯根系自由基产生-清除平衡的失衡程度,降低超氧阴离子(O₂^·-)产生速率、丙二醛（MDA）含量,减弱干旱对生长发育的抑制,增强植株整体抗旱性,同时马铃薯块茎重量得到显著提高。（2）干旱胁迫影响干物质在马铃薯地上、地下部的分配,导致地下部生物量增加,同时增加根冠比。增施钾肥、磷肥可显著提高植株地下部干重,但各处理间根冠比无显著差异。增施钾肥能显著增加干旱胁迫下马铃薯总根长、根体积、根表面积和根直径,但高钾对中旱下总根长、根尖数表现出负效应。施磷亦能显著增加干旱胁迫下马铃薯总根长、根体积、根表面积和根直径。高磷对正常水分下根直径、干旱胁迫下根尖数表现出负效应。值得指出的是,与钾肥相比,磷肥促根伸长的效应更为显著,中旱下施磷量与总根长之间呈显著正相关。（3）比较包括对照在内的6种钾肥和磷肥增施量,以每公顷增施202.5 kg钾肥（K₂O）和153 kg磷肥（P₂O₅）对马铃薯幼苗抗旱性及生长发育的促进效果最佳。通过在正常灌溉下设不施氮和大田常规两个对照以及1:0、0:1、1:5.7、1:1.2、1:0.54共5个氮肥基追比处理,研究了马铃薯植株的农艺性状和根系生理状况,结果表明:（1）马铃薯施氮应采取基、追肥并重的方式,氮肥一次性基施和全部于生育期内追施均不利于根系生理活性的提高和块茎产量的形成。（2）在不同氮肥基追比作用效果的对比研究中,以65%氮肥作基肥,35%氮肥作追肥（即氮肥基追比为1:0.54）最有利于马铃薯根系的建成,在保证植株地上、地下部分协调、均衡发育的同时还能获得更大产量,收获指数更高。更多还原

【Abstract】 The experiments were carried out from 2016 to 2017 at Tiaoshan experimental station（37°11’N,104°03’E）,Baiyin,Gansu province,to evaluate the growth and development indexes as well as root physiology and root morphological characteristics of Potato（Solanum tuberosum L.cv.Cultivar Atlantic）under different levels of K and P fertilizer applications under drought stress and various ratio of N basal fertilizer and topdressing fertilizer under normal irrigation.The main conclusions of our experiments were as follows:The experiments were conducted in a plastic greenhouse and potato materials were subjected to six K levels:0、1.2、2.4、3.6、4.8、6.0g（per plant）and six P levels 0、0.485、0.97、1.455、1.94、2.425 g（per plant）under three water conditions:normal irrigation（taken as contrast）,mild drought and moderate drought respectively.Responses concerned potato root resistant physiology,morphological characteristics and plant biomass accumulation along with tuber yield were illustrated and the results indicated that,potato growth and dry matter accumulation above ground were inhibited to some extent with the water deficit,while applications with proper dosage of P,K fertilizer could improve the root water content and root vigor,alleviate the imbalances of free radical generating and scavenging by enhancing the activities of SOD,POD and CAT,reduce the producing rate of O₂^·-as well as MDA content.Attenuate the inhibition on the potato growth and development caused by drought,enhance the overall drought resistance of plants,thus,the potato tuber weight was significantly increased.Drought stress affected the distribution of dry matter in potato over and under ground,resulted in the increase of biomass of underground parts.Meanwhile the root to shoot ratio enhanced.The application of K and P fertilizer could also improve the dry weight of underground parts,however,there were no significant differences in root to shoot ratio under different K fertilizer levels and different P levels.In the aspect of potato root morphological development,the total root length,root volume,root surface area and root diameter increased under K treatments,on the whole.But the high K application amount showed a negative effect on the total root length and number of root tips under moderate drought.P fertilizer could increase the total root length,root volume,root surface area and root diameter of potato as well within limits,nevertheless,a high P dosage showed a negative effect on the root diameter under normal irrigation and number of root tips under drought stress.Deserve to be mentioned,compared to K fertilizer,the effect of P on root elongation was more significant.There showed a significant positive correlation between P application amount and total root length under moderate drought.Comparing the six P and K application levels with contrast,it was the best to promote the potato drought resistance and growing development with 202.5 kg K（K₂O）fertilizer and153 kg P（P₂O₅）fertilizer per hectare.In addition,This study evaluated the agronomic trait and root physiological status of potato cultivar Atlantic grown under normal irrigation conditions among 7 N fertilizer treatments including two control groups:N-deficient（no nitrogen applied）and conventional field N treatment along with five different ratio:1:0、0:1、1:5.7、1:1.2、1:0.54N basal fertilizer and topdressing.It turned out that,Neither single N basal fertilization or full amount apply during growth period would not be beneficial to the improvement in root physiological activity and formation of tuber yield.In the study of effects concerning different N fertilizer application models,65%N using as basal fertilizer and 35%using as topdressing fertilizer was most favorable for the establishment of potato root system.In addition to guaranteeing a coordinating and balanced development between overground segment and underground segment,a higher tuber weight and harvest indexes could be obtained at the same time.更多还原