Study On Pear Fruit Development And Characteristics On Quality Formation In Greenhouse

Pear tree cultivation in greenhouse was originated from Japan.In our country,its physiological basis and cultivation techniques were unsubstantial relatively,because this cultivation mode was beginning just now.Pear trees cultivation in greenhouse could avoid wind calamity to a certain extent in coastland,make pear fruits come into the market earlier. improve fruit sale price and economic benefits.In this paper,fruits of early ripening pear cultivars 'Zaosheng xinshui' and 'Cuiguan' were used as materials to study the temperature in greenhouse,lamina chlorophyll and carotenoid content,fruit horizontal diameter,fresh weight and fruit cell size,fruit sugar and organic acid and other nutritional components,SS activity in synthetic direction and SPS activity and so on,the results as followings:1.Average temperature per day in greenhouse was higher than that in field,especially the early temperature difference.2.The shape curve changes of total chlorophyll,chlorophyll a and chlorophyll b in lamina were consistent each other;and chlorophyll b content was lower than chlorophyll a content.But the difference in different cultivars was significant,at fruit ripeness,content of lamina chlorophyll a,chlorophyll b or total chlorophyll of 'Zaosheng xinshui' in greenhouse was lower than that in field,but 'Cuiguan' was opposite.No matter in greenhouse or in field,the ratio of chlorophyll a to b of 'Zaosheng xinshui' or 'Cuiguan' lamina was 3 to 1.Lamina carotenoid content was almost the same both in greenhouse and in field.3.The growth curves of fruit horizontal diameter were 'S' shapes.During fruit ripeness,fruit horizontal diameter of 'Zaosheng xinshui' in greenhouse was smaller than that in field;but the both of 'Cuiguan' was near.Comparing with field,fruit development period in greenhouse was shorter,fruit cell division period was longer and the division speed was quicker.The fresh weight of 'Zaosheng xinshui' mature fruits in greenhouse was lower than that in field;but 'Cuiguan' was opposite and the both difference was significant highly.4.At fruit ripeness,the total sugars in fruit were accumulated mainly with fructose and sucrose.Meanwhile,total sugar content of 'Zaosheng xinshui' in greenhouse was higher than that in field,but total sugar content of 'Cuiguan' was opposite.The content of fruit organic acid in greenhouse was lower than that in field.The content of fruit starch,which was different in cultivars,referring to 'Zaosheng xinshui' in greenhouse was lower than that in field,but 'Cuiguan' was reverse.The change of fruit vitamin C content showed 'up-down' shape curve,at fruit ripeness,the difference of 'Zaosheng xinshui' vitamin C content between greenhouse and field was significant.Fruit rigidity of 'Zaosheng xinshui' in greenhouse was lower than that in field;however,'Cuiguan' was opposite.Soluble solid content of 'Zaosheng xinshui' in greenhouse was higher than that in field;and it was reverse in 'Cuiguan'.5.Comparing with greenhouse,sucrose accumulation of 'Zaosheng xinshui' or 'Cuiguan' had a significant positive correlation,a highly significant positive correlation to SS activity in synthetic direction and SPS activity respectivly in field.At fruit ripeness,SS activity in synthetic direction and SPS activity,sucrose content of both cultivars in field was higher than that in greenhouse respectively.6.At fruit ripeness,the total sugar content in pericarp was accumulated mainly with fructose and glucose.Meanwhile,pericarp total sugar content of 'Zaosheng xinshui' in greenhouse was higher than that in field significantly,but which was lower in 'Cuiguan' significantly.The content of pericarp organic acid in greenhouse was higher significantly than that in field in both cultivars.No matter 'Zaosheng xinshui' or 'Cuiguan',pericarp chlorophyll or carotenoid content had a significant negative correlation to pericarp fructose, glucose and total sugar content,and the correlation value was bigger in greenhouse.7.Luster of fruit surface in greenhouse was improved.Comparing with field,tending red colour value of 'Zaosheng xinshui' pericarp was smaller in greenhouse,but tending yellow colour value was bigger.Tending green colour value of 'Cuiguan' pericarp was bigger in greenhouse and both tending yellow colour value was near.The contents of chlorophyll and carotenoid in pericarp were lower in greenhouse.In total,fruit colour and luster in greenhouse was better than that in field from the visual perspective.