Mechanism Of Quality Formation Differences And Regulation Measures In Different Quality Types Of Peanut

As an important economic crops and oil crops in China, the production of peanuts ishighest in all oil crops. One of the main application of peanut seed in the national economy isfor the oil expression, the other is as raw materials for the food industry and the third is forexport. The varieties mainly used for oil expression require the oil content as higher aspossible, the varieties mainly used for edible require higher protein and lower fat in seed, thevarieties mainly for export require O/L as higher as possible. There are great differences inyield and quality of different quality types of peanut，and there is a significant negativecorrelation between yield and quality in different quality traits. The different planting patternsalso have influence on the yield and quality of different quality types of peanut. In this study,two planting methods (plastic film mulching system of spring seeded and open cultivationsystem of spring seeded) have been used in large area of the peanut production. Threecultivars (high-protein cultivar KB008, high-fat cultivar Hua17and high O/L cultivarNongda818) were selected and used as materials. The differences of physiologicalcharacteristics, carbon and nitrogen metabolism enzyme activities, yield and quality, and thedifferences of protein body and lipid body accumulation in cotyledon cell of different qualitytypes of peanut were studied. The physiological basis, enzymology basis and cytological basisof the differences in forming yield and quality of different quality types of peanuts, thephysiological basis and enzymology basis of effects of film mulching on yield and qualitywere definitude. It not only had the important theoretical significance to making up for thedeficiency of quality physiology study of peanut, but also had practical guiding significancefor the production of high-quality peanuts. Aiming at lodging and premature senescence in thepeanut production, the effects of spraying paclobutrazol and seaweed fertilizer on yield andquality of different quality types of peanuts were studied, to detect the regulation mechanismand put forward proper control strategy of production increasing and quality improvement, inorder to provide technical guidance for the production of peanut. Experiments were carried out from2009to2012in experimental station of Shandong Agricultural University, and themain results are as follows.1Differences of physiological characteristics in leaves of different quality types of peanut1.1Differences of photosynthetic characteristics of different quality types of peanutThe photosynthetic rate, actual photochemical efficiency and maximal photochemicalefficiency of different quality types of peanut showed a single peak curve. The Pn of threecultivars was ranked as H17>818> KB008. The Pn of H17and818was significantly higherthan KB008before30d after anthesis, but the Pn of KB008was higher than H17and818after45d after anthesis. The ФPSⅡof KB008at15d after anthesis was significantly higherthan that of H17and818, and the ФPSⅡof three cultivars was ranked as H17>818> KB008at45d after anthesis. The Fv/Fm of three cultivars was ranked as818> H17> KB008at podsetting stage, but was ranked in the order of KB008> H17>818at mature stage.The content of chlorophyll of three quality peanut varieties was ranked in the order ofH17>818> KB008during the whole growth period, but the content of chlorophyll of KB008was significantly higher than the other two varieties after pod filling stage.1.2Differences of soluble sugar and nitrogen content in leaves of different quality types ofpeanutThe content of soluble sugar in leaves of KB008was the largest, followed by H17and818. The content of nitrogen in leaves of KB008was significantly larger than that of H17and818.1.3Differences of leaf senescence in different quality types of peanutThe activities of POD and CAT in leaves of H17and818was little higher than that ofKB008. MDA content of KB008was significantly lower than that of H17and818, while theactivity of SOD and content of soluble protein were higher than those of the other twovarieties, which caused the high protein variety slower senescence.2Differences of carbon and nitrogen metabolism enzyme activities in leaves of differentquality types of peanut2.1Differences of nitrogen metabolism enzyme activities of different quality types of peanutThe activities of NR, GS, GOGAT, GPT and GOT in leaves of KB008were apparentlyhigher than those of H17and818, the activity of nitrogen metabolism enzyme between H17 and818had little difference. That was the enzymology fundamentals of high protein varietyto accumulating higher protein content of seeds.2.2Differences of carbon metabolism enzyme activities of different quality types of peanutThe activities of SS and SPS in leaves of three varieties were ranked in the order ofH17>818> KB008, especially the activity of SPS had a greater difference. The activity ofPEPCase in leaves of three varieties was ranked in the order of KB008>818> H17. Theactivity of RuBPCase in leaves of three varieties was ranked in the order of H17>818>KB008during the whole growth period.3Differences of yield and quality of different quality types of peanut3.1Differences of yield and yield components of different quality types of peanutThe pod yield of H17was highest, while the yield of KB008was significantly lower thanthat of H17and818, which was mainly caused by less pods of per plant and smaller pod. Thepod kernel rate of KB008was significantly lower than the other two varieties, but the doublekernel rate was significantly higher than H17and818.3.2Differences of seed quality of different quality types of peanutThe protein accumulation rate was faster than the fat accumulation of KB008at maturestage, while the fat accumulation rate was greater than the protein accumulation of H17and818. This behaved that the high protein variety continue to increase protein content but fatcontent is slightly lower at mature stage, while the fat content continue to increase and theprotein content decrease slightly of high fat and high O/L variety.All kinds of amino acid content in KB008were the highest, especially glutamic acid,lysine, leucine and phenylalanine content. This showed the content of essential amino acidsfor human body in high protein variety was obviously higher than that of high fat and highO/L varieties. The relative content of palmitic acid, stearic acid, linoleic acid, arachidonic acidand behenic acid of KB008was significantly higher, while the relative content of oleic acidand lignoceric acid was significantly lower, compared with those of H17and818at maturestage.4Differences of cotyledon cell ultrastructure in different quality types of peanut under filmmulching cultivation The protein bodies in cotyledon cells of three varieties entered the fast accumulationstage from20days the pegs struck into the soil to40days. The difference of the size andnumber of protein bodies in three varieties were smaller and less before30days the pegsstruck into the soil but became larger and more after30days. The size and number of proteinbodies of KB008was significantly greater than that of H17and818, which illustrated that thebigger size and number of protein bodies was the cytological basis of KB008have higherprotein content.The size of lipid bodies of KB008was maximizing at30d after the pegs struckinto the soil, while the size of lipid bodies of H17and818was maximizing at50d. Thenumber of lipid bodies of H17and818was still increased rapidly at50d after the pegs struckinto the soil, which showed the duration of rapid accumulation of lipid bodies of H17and818was longer than that of KB008and the number of lipid bodies is more than KB008. That wasthe cytological basis of this two varieties have higher fat content.5Effects of film mulching cultivation on physiological characteristics, yield and quality ofdifferent quality types of peanut5.1Effects of film mulching cultivation on photosynthetic characteristics of different qualitytypes of peanutFilm mulching cultivation significantly increased Pn of three varieties, especially before30d after anthesis, this showed that film mulching cultivation significantly increased the leafphotosynthesis rate mainly before the pod filling stage. The Pn of KB008under filmmulching cultivation was significantly higher than that under open field cultivation before60dafter anthesis, and the Pn of H17under two different cultivation at60d after anthesis wasbasically the same, while the Pn of818under two different cultivation was basically the sameat45d after anthesis, later the Pn under film mulching cultivation was significantly lower thanthat under open field cultivation. Film mulching cultivation significantly increased the contentof chlorophyll of three varieties, especially before45d after anthesis, this was the basis reasonwhy the film mulching cultivation significantly increased the photosynthetic rate. The rapiddecline of chlorophyll content was the main reason leading to the decrease of photosyntheticrate after pod filling stage.5.2Effects of film mulching cultivation on leaf senescence of different quality types of peanut Film mulching cultivation increased the activities of SOD, POD and CAT in leaves ofKB008, while reduced the content of MDA at pod filling stage. Film mulching cultivationreduced the activities of SOD and POD, increased the content of MDA, this showed thatdifferent quality types of peanut under film mulching cultivation were confronted with obvioussenescence.5.3Effects of film mulching cultivation on nitrogen metabolism enzyme activities of differentquality types of peanutFilm mulching cultivation increased the activities of GS, GOGAT and GDH of threevarieties at pod setting stage. Film mulching cultivation slightly reduced GS and GOGATactivities of KB008at pod filling stage, significantly reduced GS activity of H17and818.Plastic film mulching significantly increased the activities of GOT and GPT of3varieties atpod setting stage, significantly increased the activities of two enzymes of KB008at podfilling period, while slightly decreased GOT activity of H17and818at pod filling stage.5.4Effects of film mulching cultivation on carbon metabolism enzyme activities of differentquality types of peanutFilm mulching cultivation significantly reduced the activities of SS and SPS, this was theenzymatic reason why the film mulching cultivation could reduce the content of fat andsoluble sugar in kernels of three varieties of peanut. The SPS activity of818at pod fillingstage was decreased biggest by plastic film mulching cultivation. Film mulching cultivationslightly raised the PEPCase activity of3varieties at pod setting and filling stage, significantlyincreased the RuBPCase activity of KB008and H17at pod setting and filling stage, butslightly decreased RuBPCase activity of818at pod filling stage.5.5Effects of film mulching cultivation on yield and quality of different quality types ofpeanutFilm mulching cultivation significantly increased the pod yield of three varieties ofpeanut, increased the pod yield by6.94%of KB008,12.26%of H17, increased by9.75%of818. The ways of film mulching cultivation increasing the pod yield were different: filmmulching cultivation increased yield of high protein variety significantly because of theincrease of pod number of per plant; the main reason of increasing yield of high fat varietyand high O/L variety was the significantly increasing of pods per plant and double kernel rate. Film mulching cultivation increased pod kernel rate of high fat variety and high O/L varietybut reduced that of high protein variety.Film mulching cultivation increased the protein content but reduced the fat and solublesugar content of different quality types of peanut. Film mulching cultivation increased theO/L rate of high fat variety and high O/L variety but decreased the O/L rate of high proteinvariety. Film mulching cultivation increased the content of8kinds of essential amino acidcomponents in KB008and H17, increased the content of methionine, threonine, valine,phenylalanine and glutamic acid of818. Plastic film mulching cultivation decreased therelative content of palmitic acid and arachidonic acid, and increased the relative content ofstearic acid, arachidic acid and lignoceric acid of3varieties of peanut. Film mulchingcultivation increased linoleic acid content, but reduced the oleic acid content of KB008, whileincreased oleic acid content but reduced linoleic acid content of H17and818.6Effects of spraying PBZ on physiological characteristics of different quality types of peanut6.1Effects of spraying PBZ on photosynthetic characteristics of different quality types ofpeanutPBZ treatment significantly increased the photosynthetic rate of three varieties beforepod filling stage but increased it little after this stage even decreased it at mature stage. PBZtreatment increased the actual photochemical efficiency at whole stage and the content ofchlorophyll a and a+b of three varieties at pod filling stage. PBZ treatment increased thecontent of chlorophyll of KB008significantly, but didn’t increase it significantly of H17and818.6.2Effects of spraying PBZ on root vigour of different quality types of peanutPBZ treatment significantly increased the root vigour of different quality types of peanutat pod filling stage. The increment of root vigour was ranked in the order of H17>818>KB008at pod filling stage by spraying PBZ. The root vigour significantly increased byspraying PBZ was one of the prime reasons of PBZ treatment which significantly increasedthe pod yield.6.3Effects of spraying PBZ on leaf senescence of different quality types of peanutPBZ treatment significantly increased the activities of SOD, POD and CAT anddecreased the content of MDA of H17and818at mature stage, while reduced the activities of this three kinds of protective enzymes but increased MDA content of KB008. This showedthat spraying PBZ could delay the process of senescence in high fat and high O/L varieties,but the leaves of high protein variety had the tendency of senescence intensifies at maturestage.6.4Effects of spraying PBZ on nitrogen metabolism enzyme activities of different qualitytypes of peanutPBZ treatment increased the activity of GOGAT but significantly reduced the activitiesof GS and GDH of three varieties at pod setting stage. The activities of this three kindsenzyme was all reduced by spraying PBZ at pod filling stage. PBZ treatment reduced theactivities of GOT and GPT of three varieties at pod setting and filling stage. Spraying PBZreduced the activities of GS, GDH, GOGAT, GPT and GOT of three varieties at pod settingstage and pod filling stage was the enzymatic reason of PBZ treatment which reduced thecontent of protein.6.5Effects of spraying PBZ on carbon metabolism enzyme activities of different quality typesof peanutPBZ treatment significantly increased the activities of SS and SPS of three varieties atpod setting and filling stage. The increment of activities of SS and SPS was ranked in theorder of818> H17> KB008by spraying PBZ, which was the reason of the difference of thefat content in different quality types of peanut by spraying PBZ. PBZ treatment increased theactivities of PEPCase and RuBPCase of KB008, but increased this two enzyme activities ofH17and818major at pod setting stage, which had a decline at pod filling stage. SprayingPBZ increased the activities of PEPCase and RuBPCase of three quality types of peanut wasthe enzymatic basis of PBZ treatment which increased the pod yield.7Effects of spraying PBZ and SM6on yield and quality of different quality types of peanut7.1Effects of spraying PBZ and SM6on yield and yield components of different quality typesof peanutSpraying PBZ, SM6and PBZ+SM6all increased the pod yield of three quality types ofpeanut. PBZ+SM6treatment was the best control measure, increased yield maximally, thesecond was PBZ. The number of pods per plant of H17and818increased the mostsignificantly by PBZ and PBZ+SM6treatments, while separate spraying SM6had little effects on this two varieties. Spraying SM6increased the number of pods per plant of KB008most. PBZ treatment reduced the kernel rate of KB008and H17but slightly increased it of818. Spraying SM6significantly improved the kernel rate of three varieties.7.2Effects of spraying PBZ and SM6on seed quality of different quality types of peanutSpraying PBZ, SM6and PBZ+SM6all increased the content of fat and reduced thecontent of protein of three quality types of peanut. The effects of spraying PBZ, SM6andPBZ+SM6on protein content of KB008were not significant, but decrement of proteincontent of818was greater by sprayed PBZ, while decrement of protein content of H17wasgreater by spraying SM6. The fat content of three varieties by spraying SM6was increasedmost significantly, while separate spraying PBZ increased minimum. PBZ treatmentsignificantly increased the content of soluble sugar of three quality types of peanut but SM6significantly reduced the content of it. SM6treatment improved the rate of O/L of threequality types of peanut. PBZ treatment reduced the contents of8kinds amino acidcomposition of KB008and H17. SM6treatment significantly improved the content of oleicacid but reduced the content of linoleic acid of three varieties. PBZ treatment reduced thecontent of oleic acid but improved the content of linoleic acid of818.