关键词: 李, 裂果, 组织细胞生长速率, 可溶性固形物, 土壤水分, 氢氧化钙, 硼砂

Abstract: Relationships among cell growth of fruit, water, or total soluble solid ( TSS) with cracking of Prunus salicina L. were studied. Tissue anatomical characteristics of cracking fruitwere observed. Effects of spraying borate or calcium hydroxide solutions and rain shield on trees for reducing cracking incidence were tested. The resultswere as follows: 1. Anatomical observations and micro-measurements showed that, uncoordinatedly growing between the outer dermal tissue of fruit and inner parenchyma caused fruit cracking. Compared with ‘Jilin 6’and ‘Suilinghong’, inner parenchyma cells of‘Suili 3’grew significantly more faste during rapidly growing period ( P < 0.05) while epidermis grew slowly or stops developing. In addition, there exists bigger interspace of cutin decorations on surface of‘Suili 3’, potentially becoming break through point of cracking. In this way, combination of internal turgor forces caused by inner rap id growth acting on the fruit surface with the loss of skin elasticity caused fruit cracking. 2. TSS contents in cracking fruits are significantly higher than that of normal fruits ( P < 0.05) , suggesting that higher TSS may easily induce fruit cracking. 3. ‘Suili 3’fruit cracking may be reduced through spraying of borate at 0.5 mg/L. However, spraying calcium
hydroxide solutions had no effect in reducing fruit cracking. 4. It is positive-correlated between soil moisture and the incidence of the cracking ( P < 0.05) in August when fruits of‘Suili 3’was nearly mature; plastic rain shield and ditches may effectively reduce fruit cracking of‘Suili 3’, suggesting that water is a driving factor that caused fruit cracking.

Key words: Prunus salicina L., Fruit cracking, Growing rate of tissue, TSS, Soil moisture, Calcium hydroxide, Borate