Studies On The Physiological Property Of Golden Pear During Fruit Growth, Development And Storage

Golden pear is a new variety from South Korea, which belongs to sandy pear. The fruit is well known by its high quality, so it has a high potential to be developed. In this experiment, the physiological property of golden pear was studied. The main results were as follows:1. The growth curves of golden pear showed an "S" shape. The growth of diameter and length had experienced 3 stages, it showed a trends of "quick-slow-quick"; fresh weight and fruit volume grew slowly at prophase, then their growth was accelerated from 70 days after bloom to fruit ripening.2. Cell division would stop from 25 days after bloom. After that, the fruit grew by the growing of cell volume.3. The development of fruit spot had experienced 3 stages; it could be formed till 45 days after bloom. Stone cell development started from 15 days after bloom; when 40 days after bloom, the diameter of stone cell group would not raise again, and after that the density of stone cell group would dropped apparently.4. The changes of fruit inclusion content and firmness during fruit growth and develop -ment were as follows: (1) In the early stage of fruit development, the changes of the soluble sugar were not obvious; from June 14 to fruit ripening, soluble sugar accumulated rapidly. The main ingredient of sugar in fruit is fructose, glucose and sucrose, and the content of fructose is the highest. (2) The content of titratable acid was high at the beginning. With the development of fruit, titratable acid content decreased, and it increased lightly near fruit ripening. (3) During fruit development, the starch content was raised apparently first, with the fruit growing, most of it changed to sugar, and its content decreased evidently and quickly. (4) With the development of fruit, the content of soluble solid increased and the fruit hardness decreased. (5) The content of Vitamin C dropped in early development stage, and it increased evidently before harvest. (6) In the early stage, there is a peak of lignin content, and after the peak lignin content was reduced; and the content of phenol showed downtrend all through the fruit development.5. Respiratory climacteric came forth during fruit ripening and storage: the maximum value of ethylene production and respiratory rate appeared successively, so golden pearbelonged to climacteric fruit.6. Stored at room temperature, the golden pear would be rotted soon after 10~14 days. During this time, the weight loss ratio increased rapidly; the fruit firmness decreased speedy at storage prophase then slow down; and soluble solid content went up slightly; respiratory rate value arrived to its maximum in 2 days after harvest, then declined; ethylene production grow up when the fruit began to be rotted; LOX activity appeared two peaks, PG activity increased rapidly, then fell down a little, PME activity slow down quickly at first, then slowly.7. Golden pear could keep high quality over 100 days if stored at 5 centigrade, because the low temperature had influenced it in many aspects: (1) Made weight loss ratio lower than normal, and no fruit rot appeared; (2) Keep high fruit firmness all through the storage; (3) Respiratory climacteric came forth later than that which stored at room temperature, and the peak was lower than normal; (4) Activity of LOX and PG were inhibited, so the process of fruit senescence was delayed effectively.