The Basic Studies On Sexual Hybridization Breeding In Shallot

Several shallot varieties collected from Liaoning province and Heilongjiang province were applied to study the effect of the different temperature and different hormone treatments on bolting and flowering in this thesis. The results reached here can be of some use for the breeding practice of shallot. In addition, a new shallot hybrid was selected and it was named as’Zhucong No.1’. The main results of the research were as follows:1. Two varieties of shallot were treated at-3--5℃、2-4℃and8-10℃for two months. The results showed that temperature had impacted on the biochemical indicators of shallot. In the range of2-4℃, the soluble sugar content and soluble protein content was the highest, C/N ratio was the maximun value, and peroxidase (POD) activity was the strongest.-3--5℃、2-4℃、8-10℃, these three temperature treatments did not promote shallot bolting and flowering.2. The bulbs of shallot were treated at2-4℃for60days, and then immersed in gibberellin (GA3) solutions of50、500and1000mg·L-1for24hours. The biochemical indicators were improved at the three concentrations of GA3. The results showed that the best treatment was GA3concentration at500mg·L-1. The GA3of500and1000mg·L-1could promote cv.’Chengzi’and’Lalin’to bolting and the bolting rate was20-40%. The cv.’Yilan’demonstrated the resistance to bolting. The flowering rate in bolted plants was100%. The CMS line plants were pollinated and hybrid seeds were harveseted on the CMS line plants.3. The bulbs of shallot were treated at2-4℃for60days, and then immersed in abscisic acid (ABA) solutions of0.3、3and30mg·L-1for24hours and the biochemical indicators were improved and the bolting and flowering were observed. The results showed that the best treatment was ABA concentration at3mg·L-1. The soluble protein content was increased in the ABA of30mg·L-1, and other biochemical indicators were decreased at this treatment. The ABA of0.3and3mg·L-1could promote cv.’Chengzi’ and’Lalin’to bolting and the bolting rate was20-50%. The cv.’Yilan’demonstrated the resistance to bolting. The flowering rate in bolted shallots was100%. The CMS line plants were pollinated and hybrid seeds were harveseted on the CMS line plants. 4. The bulbs of shallot were treated at2-4℃for60days, and then immersed in indolylacetic acid (IAA) solutions of5、50and500mg·L-1for24hours. The biochemical indicators were improved at the two concentrations of IAA (5and50mg·L-1). The results showed that the best treatment was IAA concentration at50mg·L-1. The C/N ratio was decreased in the IAA of500mg·L-1, and other biochemical indicators were increased at this treatment. The IAA of50mg·L-1could promote cv.’Chengzi’and ’Lalin’to bolting only and the bolting rate was20%. The cv.’Yilan’demonstrated the resistance to bolting. The flowering rate in bolted plants was100%. The CMS line plants were pollinated and hybrid seeds were harveseted on the CMS line plants.5.’Zhucong No.1’was a new shallot hybrid that crossed male sterile line ’MB01-79A’ with inbred line’WMF01-06C’. It was suitable for planting in the lower temperature area of the provinces of Jilin, Heilongjiang and Neimenggu, and growing under the conditions of long day. It required130-140days for maturity. Compared to the control of conventional cultivar, it had stronger resistance to pest disease, and it was storable. Its yield was higher and its bulbs number was less. The commodity rate of the new shallot hybrid has been raised greatly.’Zhucong No.1’was more suitable for export.