Preliminary Study On Techniques Of Cross Breeding And Selection Of New Cultivars In Gerbera Jamesonii

Gerbera jamesonii was used widly as cut flower and worthy of breeding .In terms of raising theoretical reference, techniques of cross breeding ,selection of new cultivars in Gerbera jamesonii have been preliminary studied .By the investigation,the results indicated that the inflorescence developmental could be classified into the following stages :flower budding ,side-ligulifloret and involucre in the samelength ,ligulifloret extend out of the involucre in length ,inflorescence expanding ,and flowering .Difference of inflorescence diameter and stalk length were examined among three cultivars of Gerbera jamesonii. It was growing fast during flower budding and inflorescence expanding. The average growth time was 17 days in simple flower and 23 days in double flowers from budding to inflorescence expanding .Test in vitro of germination indicated that the most optimized culture medium was part of ME3+300 g.L -1 PEG1500 and part of ME3+200 g.L -1 PEG4000. The highest germination rate in N2 was 38.3%. Effect of different flowering stages on pollen viability was significantly. when the pollen was reserved within 30h, it's good living ab ility was still maintained .The pollen living ability declined with time prolonging and the best condition for pollination was 22~28℃and fresh pollen appearing .By means of benzidine- hydrogen peroxide reaction and aniline blue fluorescence method, showed that the stigma receptivity could teach to 12 days since flowering. Compared with self pollination, the pollen was easily adhered into sigma and the pollen tube was easily entered into style in cross pollination experiment. Emasculation could not effect on the development of stigma and the cut of petal could prolong the time of stigma development by observation to N13.That pollination could be carried out during the whole year in green house while the optimized period was in Spring and Autumn. Seed set could be found out both in cross and self-pollination(different individuals within one cultivar ) plants, while 1000-seed weight was lower in self pollination. Seed setting rate were different among different maternal cultivars, they were performed as: simple >half-double >double types. Seed germination was affected by storage time significantly .Germination of fresh seeds was more than 90%.The seeds could not be stored for a long time and the number of germination was 50% or so when seeds were cold stored .We can infer through analyzing the inheritance of some character of Gerbera jamesonii that the expression of red flower color of hybrids somewhat trended to that of female parents , plant height,flower diameter and flower doubleness had a declined tendency .The phenomena that over parent individuals color ,plant height ,flower diameter and flower doubleness emerging are beneficial to the choice of new cultivars .Via estimating and choosing the offspring of Gerbera jamesonii ,six relatively good individuals had been chosen out .