Effect Of Soil Temperature On Physiological And Biochemical Indexes Of Zaolupan Flat Peach During Dormancy And Raising Temperature Period In Greenhouse

The effect of soil temperature on physiological indexes and morphological development of flower buds was studied with 2-3 years old trees(Prunus persica var. compressa cv.Zaolu.) from onset of dormancy to bud break. The main physiological indexes of flower buds in greenhouse were compared to those of flower buds in field. The main results were as follows:1. Soil temperature influenced dormancy completion of flower buds. The indexes of bud break with CK and 15 treatments kept rising with the accumulation of chilling requirement. Withl5 treatment, on December 19, the indexes of bud break of flower and leaf buds were 30.61% and 34.09% respectively, and thus the dormancy was broken. With CK, on December 26, the index of bud break of leaf bud was 30.72%, and dormancy was broken. However the dormancy of flower bud was broken on December 30. The result showed that 15 treatment accelerated dormancy completion.2. Soil temperature influenced development of floral organs. Both 15 and 20 treatments accelerated flower buds expanding and development of the anthers, flowered earlier with 5-6 days, and improved pollen vitality and pollen germination rates and decrease numbers of pollen. However the effect of 15 treatment was better.3 In flower buds, the maximal value of soluble sugar contents with 20'C and 15 treatments appeared earlier than that with CK, which caused that 20 and 15 treatments could break dormancy of flower bud earlier. The result showed that the appearance of maximality of soluble sugar content was the sign of dormancy breaking. During dormant period, contents of soluble sugar, starch, protein and amino acid with 20 treatment were lowest among the three treatments.4 Similar trends were found: that with the three treatments SOD activities kept descending; POD activities rising; IOD activities descended firstly and then increased rapidly. On December 10 , IOD activities achieved to the lowest, which was coincidedwith the time when flower bud dormancy was broken.5 With the accumulation of chilling requirement, the total water content kept rising gradually, the bound water content increased rapidly and kept higher level for a period, and then descended gradually, the free water content descended firstly, however rose rapidly before flower bud dormancy was broken with both CK and 15 treatments.. The initial time of bound water content descending and free water content increasing was earlier with 15 treatment. The results showed that the changes of bound water and free water contents could be used as a reference sign of dormancy breaking.6 During dormant period, IOD activities with 15 treatment kept at a lower level in root system, .and SOD activities with 15 treatment changed extent, yet those with CK changed steadily. No difference were POD changes between CK and 15 treatments before December 30, however after December 30, those descended rapidly withl5 treatment, those kept higher with CK. The results showed that 15 treatment was effect of development of root systems.7 In flower buds, the maximality of contents of soluble sugar and amino acid, and the lowest value of contents of starch and protein in greenhouse appeared earlier than those under field. The results showed that dormancy was broken in greenhouse earlier than field.