水培营养液离子浓度对脱毒马铃薯生长发育和光合性能的影响

摘要

Effects of different ironic concentration of nutrient solution on the growth and photosynthetic characteristics of potato were analyzed to clarify the physiological mechanisms of adaptability of virus-free potato,which would provide a theoretical basis for the potato cultivation under hydroponic system.Taken early maturing variety ‘ Yushu No.5’ and late season variety ‘ E’shu No.1'as plant materials,the effects of different ironic concentration of nutrient solution on growth and development,root activity,photosynthetic characteristics and chlorophyll fluorescence of virus-free potato by hydroponic were studied.The result showed that the numbers and production of micro-tuber per plant were the highest at an integrate ionic concentration of 3475.00 mg · L-1 (EC =2.91 ms · cm-1) compared with ultra treatments;During tuber expansion period,the root activity,net photosynthetic rate (Pn),maximal photochemical efficiency (Fv/Fm),actual photochemical efficiency (φPS Ⅱ),electron transport rate (ETR) and photochemical quenching (qP) of this treatment were all increased as well.Under high ironic concentration of 4248.51 mg · L-1,the vegetative growth and chlorophyll synthesis were promoted,and the number of stolons per plant were increased,but the tuber initiation was inhibited,and the stage of tuber formation was delayed;With low concentration of nutrient solution (C≤2124.26 mg · L-1),the early initiation and formation of tuber,but leaf area per plant,root activity,Pn,Fv/Fm,φPS Ⅱ,ETR,qP and numbers of stolons per plant were all decreased significantly so that the production of micro-tuber was reduced.Optimum ionic concentration of nutrient solution was 3475.00 mg · L-1 (EC =2.91 ms · cm-1) in the whole period;Improving the ionic concentration in vegetative period and reducing during tuber expansion period was a key method to raise the yield of micro-tuber by hydroponic.%通过研究不同离子浓度的营养液对水培马铃薯植株生长发育、叶片光合性能和结薯性能的影响,明确水培马铃薯在各个生长发育期对营养液离子浓度的要求,为水培马铃薯高效栽培营养液管理技术提供理论依据.本试验以早熟马铃薯品种“渝薯1号”和晚熟马铃薯品种‘鄂薯5号’为材料,研究了营养液的离子浓度对水培脱毒马铃薯植株生长发育、根系活力、光合作用、叶绿素荧光和微型薯产量的影响.当营养液离子浓度为3186.38 mg·L-1,EC值为2.91 ms·cm-1时,2个品种的微型薯数量和产量最高;在块茎膨大期,该处理下的根系活力、净光合速率(Pn)、最大光化学效率(Fv/Fm)、PSⅡ实际量子产额(中PSⅡ)、光合电子传递速率(ETR)和光化学猝灭(qP)等均提高.4248.51 mg· L-1的高浓度处理虽然可以促进地上部分生长、叶绿素合成和匍匐茎形成,但不利于块茎形成,推迟结薯,还会引起早熟品种渝薯1号叶片和根系早衰.低营养液离子浓度(C≤2124.26 mg·L-1)处理可促进块茎提早形成,但植株叶面积、根系活力、Pn、Fv/Fm、中PSⅡ、ETR和qP较低,降低叶片光合速率和光化学效率,匍匐茎形成少,使微型薯产量降低.营养液离子浓度为3186.38 mg· L-1时最适合马铃薯全程生长,而在马铃薯植株块茎形成前可适当提高营养液浓度,块茎形成期和膨大期应适度降低营养液浓度,可有效提高水培马铃薯微型薯产量.