Research On The Induction Factors Of Pear Deviation

In this experiment, pear varieties of Cuiguan, Qingxiang, Xueqing, Yuguan, Huangjin, Hangqing and Mixue (Tainong-2) were studied. By investigating the regularity of deviation on pears, it was researched that the relationship among deviation and varieties, fruit growth status, fruit-bearing branch, fruit position, fruit stalk diameter-length, and seeds development process. The endogenous hormones were also determined to analyze the mechanism of deviation on pears.1 The results showed that the lopsided fruits of pears were appeared in the early days of immature fruit expansion. The dynamic swelling of deviation processed three stages:slowly-quickly-solidly. The results presumed that the immature fruit developed regularly was a basis for keeping symmetric growth, and the translocation process of fruit from up-growth to droop-growth was a key period for controlling asymmetric growth.2 The deviation among varieties was different. From the investigation of Cuiguan, Qingxiang, Xueqing, Yuguan and Huangjin pears, it was displayed that the average deviation rate among the 5 varieties was 45%, and the deviation rate of Huangjin pear showed an extremely significant different while that of Qingxiang pear showed a significant different.3 The experiment taken Huangjin pear as material to analyze the skewness, and the fruits from long-fruit-bearing, middle-fruit-bearing and short-fruit-bearing were tested. It was indicated that neither skewness nor deviation rate had no significant different.4 The fruit position would affect fruit appearance quality such as shape and size. The results manifested that the fruit shape was different when the fruit of Cuiguan pear at different positions. When the position was at the first to low-third, the fruit shape was close to each other; and the shape was applanated. But when the position was above fourth, the fruit shape was circular or cuspidal. The fruit shape at the second position was more regular and the skewness was smaller.5 Cuiguan, Qingxiang, Yuguan, Huangjin pears were used to study the relationship between fruit stalk diameter-length and skewness. The results indicated that the skewness and fruit stalk length were positive correlation; oppositely, the skewness and fruit stalk diameter were negative correlation.6 Seeds development of pear was also experimented. The results showed that the quantity of total seeds and well-stacked seeds were negative correlation to skewness and deviation rate, respectively. When the quantity of total seeds or well-stacked seeds increased, the skewness and deviation rate decreased.7 It was included from the analysis that well-growth immature fruits might grow asymmetrically. The unsymmetrical growth was aggravated when the fruit up-growth and flat-growth. Furthermore, back-to-earth could mitigate asymmetrically growth, while face-to-earth was opposite.8 The results also informed that imbalanced distribution of endogenous hormones was the internal reason which leaded to unsymmetrical growth and deviation. Compared large-flesh and facet-flesh of deviation pear, the endogenous hormones concentrations of IAA, GA3, ZT were significant higher in large-flesh; but the concentration of ABA was lower in large-flesh.9 The study also investigated the effect of smearing NAA, IBA,6-BA, CPPU, GA4+7, GA3 on immature pear. It displayed that except IAA, the growth of smear-face was obviously. In addition, the chiastic growth was obvious when smeared CPPU,6-BA; and length wise growth was obvious when smeared GA3, GA4+7.