CAJ | 학술논문

【目的】厚皮甜瓜坐果节位叶片在果实生长过程中早衰现象严重,对果实生长会造成不利影响。本试验采用外源喷施硫酸镁的方法,研究了镁对坐果节位叶片叶绿素荧光特性、活性氧清除系统及果实的影响,以期延缓坐果节位叶片衰老,提高厚皮甜瓜产量和品质。【方法】以厚皮甜瓜品种‘迎春(F1)’为试材,于坐果节位雌花开放授粉当天对植株叶片喷施不同浓度(0、2、4、6 mmol/L)的硫酸镁溶液,每7天喷1次,共喷3次,采用随机区组试验设计,重复3次。在第一次处理后每隔7d对坐果节位叶片进行各项生理指标测定。叶片叶绿素荧光参数采用成像荧光仪MINI-IMAGING-PAM测定,光合特性采用Li-6400光合仪测定,叶片镁元素含量采用电感耦合等离子体发射光谱( ICP-OES)法测定,酶含量、果实可溶性糖及可溶性蛋白测定参照李合生的方法测定,可溶性固形物采用手持糖度计测定,Vc采用2,6-二氯酚靛酚滴定法。【结果】对坐果节位叶片及果实生理指标进行分析,结果显示2 mmol/L和4 mmol/L镁处理能够显著增加坐果节位叶片的镁含量,延缓叶片衰老过程中叶绿素的降解速率；明显降低坐果节位叶片初始荧光Fo值,增强PSⅡ最大光化学效率( Fv/Fm)、 PSⅡ实际光化学量子效率(ФPSⅡ)及表观光合电子传递速率(ETR),提高坐果节位叶片的净光合速率；明显提高叶片过氧化物酶(POD)、超氧化物歧化酶( SOD)、过氧化氢酶( CAT)等抗氧化酶活性,降低活性氧和MDA含量；显著提高了厚皮甜瓜果实的可溶性糖、可溶性固形物、可溶性蛋白及Vc含量,但对单果重影响不显著。【结论】适宜浓度的镁处理能够提高厚皮甜瓜坐果节位叶片的叶绿素和镁元素含量,改善其叶绿素荧光参数和净光合效率,增强 POD、 SOD和 CAT 活性,减少H2 O2、O-·2和MDA的累积,从而延缓其衰老,并能提高果实可溶性糖、可溶性固形物、 Vc及可溶性蛋白等品质指标,但对果实产量影响不显著。【目的】厚皮甜瓜坐果節位葉片在果實生長過程中早衰現象嚴重,對果實生長會造成不利影響。本試驗採用外源噴施硫痠鎂的方法,研究瞭鎂對坐果節位葉片葉綠素熒光特性、活性氧清除繫統及果實的影響,以期延緩坐果節位葉片衰老,提高厚皮甜瓜產量和品質。【方法】以厚皮甜瓜品種‘迎春(F1)’為試材,于坐果節位雌花開放授粉噹天對植株葉片噴施不同濃度(0、2、4、6 mmol/L)的硫痠鎂溶液,每7天噴1次,共噴3次,採用隨機區組試驗設計,重複3次。在第一次處理後每隔7d對坐果節位葉片進行各項生理指標測定。葉片葉綠素熒光參數採用成像熒光儀MINI-IMAGING-PAM測定,光閤特性採用Li-6400光閤儀測定,葉片鎂元素含量採用電感耦閤等離子體髮射光譜( ICP-OES)法測定,酶含量、果實可溶性糖及可溶性蛋白測定參照李閤生的方法測定,可溶性固形物採用手持糖度計測定,Vc採用2,6-二氯酚靛酚滴定法。【結果】對坐果節位葉片及果實生理指標進行分析,結果顯示2 mmol/L和4 mmol/L鎂處理能夠顯著增加坐果節位葉片的鎂含量,延緩葉片衰老過程中葉綠素的降解速率；明顯降低坐果節位葉片初始熒光Fo值,增彊PSⅡ最大光化學效率( Fv/Fm)、 PSⅡ實際光化學量子效率(ФPSⅡ)及錶觀光閤電子傳遞速率(ETR),提高坐果節位葉片的淨光閤速率；明顯提高葉片過氧化物酶(POD)、超氧化物歧化酶( SOD)、過氧化氫酶( CAT)等抗氧化酶活性,降低活性氧和MDA含量；顯著提高瞭厚皮甜瓜果實的可溶性糖、可溶性固形物、可溶性蛋白及Vc含量,但對單果重影響不顯著。【結論】適宜濃度的鎂處理能夠提高厚皮甜瓜坐果節位葉片的葉綠素和鎂元素含量,改善其葉綠素熒光參數和淨光閤效率,增彊 POD、 SOD和 CAT 活性,減少H2 O2、O-·2和MDA的纍積,從而延緩其衰老,併能提高果實可溶性糖、可溶性固形物、 Vc及可溶性蛋白等品質指標,但對果實產量影響不顯著。
【목적】후피첨과좌과절위협편재과실생장과정중조쇠현상엄중,대과실생장회조성불리영향。본시험채용외원분시류산미적방법,연구료미대좌과절위협편협록소형광특성、활성양청제계통급과실적영향,이기연완좌과절위협편쇠로,제고후피첨과산량화품질。【방법】이후피첨과품충‘영춘(F1)’위시재,우좌과절위자화개방수분당천대식주협편분시불동농도(0、2、4、6 mmol/L)적류산미용액,매7천분1차,공분3차,채용수궤구조시험설계,중복3차。재제일차처리후매격7d대좌과절위협편진행각항생리지표측정。협편협록소형광삼수채용성상형광의MINI-IMAGING-PAM측정,광합특성채용Li-6400광합의측정,협편미원소함량채용전감우합등리자체발사광보( ICP-OES)법측정,매함량、과실가용성당급가용성단백측정삼조리합생적방법측정,가용성고형물채용수지당도계측정,Vc채용2,6-이록분전분적정법。【결과】대좌과절위협편급과실생리지표진행분석,결과현시2 mmol/L화4 mmol/L미처리능구현저증가좌과절위협편적미함량,연완협편쇠로과정중협록소적강해속솔；명현강저좌과절위협편초시형광Fo치,증강PSⅡ최대광화학효솔( Fv/Fm)、 PSⅡ실제광화학양자효솔(ФPSⅡ)급표관광합전자전체속솔(ETR),제고좌과절위협편적정광합속솔；명현제고협편과양화물매(POD)、초양화물기화매( SOD)、과양화경매( CAT)등항양화매활성,강저활성양화MDA함량；현저제고료후피첨과과실적가용성당、가용성고형물、가용성단백급Vc함량,단대단과중영향불현저。【결론】괄의농도적미처리능구제고후피첨과좌과절위협편적협록소화미원소함량,개선기협록소형광삼수화정광합효솔,증강 POD、 SOD화 CAT 활성,감소H2 O2、O-·2화MDA적루적,종이연완기쇠로,병능제고과실가용성당、가용성고형물、 Vc급가용성단백등품질지표,단대과실산량영향불현저。
[Objectives] Muskmelon leaves are often premature senescent at the fruit ripening stage, especially the leaves located on the fruiting-node, seriously decreasing the functions of photosynthetic system and fruit growth. The effects of magnesium on improving function of chlorophyll fluorescence and active oxygen scavenging system were studied. [Methods] Muskmelon cultivar‘Yingchun( F1 ) ’ was used as test material and sprayed with MgSO4 solution of 0 , 2 , 4 and 6 mmol/L on the day when female flowers on fruiting-nodes were opening and being hand-pollinated. The sprays were made once a week and 3 sprays in all. Every other week, the physiological indexes of leaves on fruiting-nodes were determined after the first spray. The chlorophyll fluorescence and photosynthesischaracteristics were measured using imaging fluorescence spectrometer MINI-IMAGING-PAM and portable photosynthesis system Li-6400, the leaf Mg content by ICP-OES method, and the enzyme activities and the contents of malondialdehyde( MDA) , soluble sugar and soluble protein in the fruits were measured referring to the LI He-sheng’s experiment method, the soluble solids with a handheld sugar meter, and the Vc content by 2, 6-dichloro phenol indophenol titration method. [Results] From analyzing physiological indexes of leaves on fruiting-nodes and fruits, the following results can be obtained: the spray of 2 mmol/L and 4 mmol/L Mg2+ could significantly increase the Mg levels in fruiting-node leaves, and delay the degradation rate of chlorophyll during the process of leaf senescence at the same time. Some chlorophyll fluorescence and photosynthesis characteristic parameters, including the maximal photochemical efficiency(Fv/Fm), quantum yield of PSII electron transport (ФPSⅡ) , apparent electron transport rate( ETR) and net photosynthetic rate are promoted at various degrees under the 2 mmol/L and 4 mmol/L Mg2+treatments, while the minimal fluorescence( Fo) is decreased dramatically. The antioxidant enzymes activities are also significantly improved, while the accumulation of active oxygen and MDA content are reduced. Additionally, the treatments mentioned above increase the accumulation of soluble sugar and soluble solids, and the contents of Vc and soluble protein in varying degrees compared with the control, but there is no significant effect on single fruit weight. [Conclusions] The treatments with proper concentration of Mg2+ could increase the contents of Mg and chlorophyll of leaves on fruiting-nodes in muskmelon, improve chlorophyll fluorescence parameters and net photosynthesis rate, heighten the activities of POD, SOD and CAT and decrease the contents of H2 O2 , O-·2 and MDA, so that postpone the leaf senescence on fruiting-nodes and enhance the fruit quality indicators of the soluble sugar, soluble solids, Vc and soluble protein, but have no prominent effect on fruit yield.