| The difference of pollen quantity of different Fragrant Pear varieties in the same year and that of the same variety in different year were investigated after a 2-3-year survey of the pollen quantity of main Fragrant Pear and their pollinating varieties in Aksu area in south Xinjiang. Meanwhile, anatomy investigation of the typical individual tree was also done, the shapes of anther, nectary and sporule were observed under microscope to study the development of anther, nectary of hybridized pear tree, mechanism of sporule failure. Certain biochemical parameters, such as disassociate amino acid, proline, catalase was determined to offer further evidence for the male-nonreproducibility. The aim of this work is to collect useful information for breeding, spatial distribution of pollinating trees in gardens, and also for the pollen development and Big-small harvest year, the result is supposed to be useful for the breeding of good variety of the Fragrant Pear. Results of this work showed that:1. The nectar gland of the Xinli No. 7 was a torus-type, well developed starch nectar, it located between stamen and style. The development of nectar and sporule were adjusted by two separate systems. The nectar gland of Xinli No. 7 had a structure similar to that of Shili, it can exudate honey, suggesting it developed normally.2. the stamen analge of Xinli No. 7 had been polarized fully in the last growth season, the dormancy terminated in early February and polarization was resumed, the miosis of the parent sporule cell occurred 15 to 25 d before blooming, i. e. in March, the quartered object came into being before the end of March. The temperature of early spring was the principal factor that affects the polarization of flower sprout of pear plant. Both the formation of the sporule parent cell and the process of quartered object formation after miosis of sporule parent were normal. No obvious difference was found between Fragrant Pear with the same reproducibility before the desegregation of quartered object. 3. the pollen development of Fragrant Pear hybrid can be grouped into three kinds: normally-developed, low-quantity-empty-pollen and fully-failed. The nomally-developed kind had big quantity of pollens, the pollens are ball- shaped and full; the low-quantity-empty kind had low quantity of pollens, with big difference in the pollen size and abnormal pollen shape; pollen of the fully-failed type collapsed at last, the anther dried, residue of pollen can also be found in anther. 4. significant difference was found between pear varieties. Pollen quantities of 10 normal pear (including one wild duli) were all greater than 1000, with the biggest value of Shili at 7471, the average was 5856. Yearly deviation of the same variety ranged between 0.25% to 141.4%, the deviation of normal pear was small, with average value at 15.9%, that of the normally developed pollen of hybrid pear was 35.5%.5. the trends of total amino acid content of Xinli No. 7 and Fragrant Pear in flower bud period were similar. During March 20 to April 1, 2001, the total disassociated amino acid kept stable, the same value increased much during March 6 to April 3, 2003. Before bud stage, the dissociated proline content of Xinli No. 7 and Fragrant Pear had similar trend, both kept rather stable. Judged from above result, we propose that early April is critical for the change in total amino acid. and proline, this period is also important for the reproducibility judgement of Xinli No. 7. Prolonged investigation in 2003 found that the content of amino acid and proline increased in early April greatly, Fragrant Pear had higher content of proline than Xinli No. 7.6. trends of catalase activity change in flower bud development stage of Xinli No. 7 and Fragrant Pear were similar, both had a pattern of quick-slow-quick, suggesting that Xinli No. 7 was still reproducible in this period. In flower bud period, the catalase activity of Xinli No. 7 changed much and began to decreased, but the catalase activity of reproducible Fragrant Pear were still inc...
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