| This experiment research content is divided into two parts. In the first part of the study,using the Chunyv2' squash as experimental material, discussed the influences of samplingtime of squash unfertilized ovary, the different parts of squash ovary and heat shock treatmentto squash unfertilized ovary induction rate, and the strengthening of the embryo training andthe domestication and transplanting of the embryo sac plant, and the technology of ploidyidentification. The results of the experiment show that:(1) The best samling time of sqush unfertilized ovary is the day before the flower bloomand the day when the flower bloomed, the embryo quantitys were23and26, and the embryorate were12.78%and12.23%respectively, and there are no significant differences betweenthem;(2)The central1/3of the squash ovary got the highest embryo quantity and the embryoinductivity, they were28and16.61%. But the first1/3and the end1/3both can induceembryo. There are significant differences between the three in0.05level, and no significantdifference i n0.01level between the first1/3and the central1/3;(3) The results of heat shock treatment show that, materials without the heat shocktreatment,67.04%ovule turn into green, the rest of the ovule still is white; And after heatshock treatment, ovule turn color rate increased significantly, among them with35℃treatment for5d got the best result, the rate of turn color can reach89.16%, and the secondone is35℃for7d, for85.78%;(4) Transfer the embryos into the strengthen medium for strengthen training, the embryosac plants can be domestication transplanted when they grow to5-7leaves, the survival ratecan reached to85.96%.The result of ploidy identification showed that in the embryo sac plantinclude haploid, diploid, polyploid and aneuploid and so on.The second part of the experiment researched on the relationship between the squashmicrospore development and the morphological characteristics of the buds, to find a quicklyand accurate way to confirm the microspore develop period. Using the Chunyv2' squash asexperimental material, collect the third buds of the male flower, surveying the length anddiameter, calculation the ratio of length to diameter, and observe the development periods of the microspores, to find out the relationship between them. Observe the periods of the buds indifferent turns to find out the differences of the lengths and the diameters in different turns.The result showed that:(1)While the peak stage of tetrad, early-uninucleate,late-uninucleate and binucleate of pollens appeared when the bud lengths were between0.95-1.05cm,1.06-1.15cm,1.16-1.25cm,1.26-1.35cm,and the breadths were between0.48-0.52cm,0.53-0.55cm,0.56-0.59cm,0.60-0.63cm. There are both significant differencesbetween the lengths or the diameters in different periods.(2)The maximum differences of the lengths or the diameters in the same period are both0.04. There are no significant differences between the buds at different turns. When themicrospore period of the Chunyv2' squash was in late-uninucleate, the cell membrane and thecell wall got more thick, and large vacuoles appeared in the cells, the nucleus was packed toone side of the cell, near to the cell wall;(3)There are relationships between the microspore periods and bud length or diameter.The length or the diameter of any bud at the first7turns can be used as a basis to judge themicrospore periods. |
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