Studies On The Pollen Morphology And Viability Of Rosa Rugosa

In this paper the pollen morphology and viability of Pingyin Rose have been studied systematically . The purposes of the study are to establish a set of quantitive criteria of pollen morphology for Rosa rugosa and check for the relationship between pollen morphology and variety evolvement , classification , the relationship between pollen morphological characteristics and plant shape , flower shape , flower color and blooming time ; and on the other hand in order to look for the best conditions of pollen storage , suitable culture medium for pollen germination and the effects of time of pollen storage on pollen viability , which are the important data for rose breeding and germ plasm resource research .Through observing vary varieties of Pinyin Rose by Olympic and Scanning Electron Micsoscope and according to the correlation analysis , we had discovered:The pollen shapes of Pingyin Rose varieties are prolate and oval or long oval in equator view , 3-labed-rounded or subrotundity in polar view . The polar axis of the pollen grams is 19.17~39.23m , and the equatorial axis 12.84~20.87m , which belong to middling near small . And 3-colposate with pore film , rectangle or subsquare inner foveola , the style of rose pollen is N3P4C5 . The exine sculpture are lirae and tectum puncture . There are significant differences in sizes, germinators and the exine ornamentation among varieties of rose pollen grains . We can use this as the important characteristics for variety identification for rose varieties .There are significant differences among pollens from 24 varieties of roses studied . The largest in size is variety of 'Xiangciguo' , with 39.23 20.87m , the smallest is 'Fenfurong' with size of 19.17 12.84m . For germinater shape , some varieties are with foveola film out-sticking and some others with foveola film sunken . There are also some differences among crannies of their germinater fossa with rectangle or subsquare shaped inner fossa . There are significant differences in the exine ornamentation among varieties of rose suchas lirae size , density, distribution , direction , tectum punctures with different density and hole diameter.According to the differences of the exine ornamentation of rose pollen grains the 24 varieties were divided into 4 groups : 1) stripes vertically paralleled with tectum puncture , 'Tangzi', 'Ziyan' and other ten varieties , 2) stripes transversely paralleled without tectum puncture , 'Tangbai' , 'Fenzhongguan' and other 6 varieties , 3)stripes distributed are inregular with tectum puncture , 'Diehongziyi' , 'Fenyunziyi' and other 4 varieties , 4) stripes distributed are inregular without tectum puncture, 'Fenfurong', 'Diefenziyi' and 'Zixiadiancui'.The results of Main Component Analysis showed that the importance ranking of the criteria is followings : fossa length , polar axis length , P/E value , equatorial axis length , distance of lirae , puncture frequency of external wall , lirae density , diameter of puncture , style of exine ornamentation , inner hole shape of gerrm'nater fossa , fossa width and L/P value . The general important characteristics are pollen size , characteristic of exine ornamentation and germinater . 24 varieties were divided into two groups acceding to the results of the Cluster Analysis . This result is similar with that of classification of plant expressive morphology.According to the correlation analysis between pollen shape of rose and their genetic characteristics , rose pollen shapes were significantly correlated with plant shape , branch color , flower color , flower shape and blooming time . Through the observation of pollens of parent plant and hybrid we found that pollen external ornamentation were significantly correlated between parents and hybrids and that means that we can use the character to identify the relation between parents and varieties .The results of off-body culture for pollen germination showed:The viability of rose pollen collected at a stage of big bud starting blooming is higher than that collected at full bloomed stage .