The Research On Plant Resources And Chromosome Ploidy Of Hibiscus In Guangdong Province

Hibiscus,a genus of Malvacae which is mainly distributed in tropic and subtropic areas.C hina,as one of the origin areas of Hibiscus,possesses long application history of Hibiscus.However,current there are less researches on Hibiscus.Thus,collecting Hibiscus plant resources and mastering the regional distribution and application of Hibiscus plant resources play a positiverole in the research and application of Hibiscus plant in Guangdong province.This thesis finds out the resources and distribution conditions of Hibiscus plantsin Guangdong Province,initially concludes the application condition of Hibiscus plants landscape based on the investigation.Using the analytic hierarchy process(AHP)principle toevaluate the ornamental value of Hibiscus as well.With the root tip as the material,the diploid chromosome number was observed.It also as a reference,finally investigate the chromosome ploidy of Hibiscus plants by flow cytometry(FCM),and analyzes the relations among chromosome ploidy of Hibiscus plants,stomatal apparatus size,corolla diameter and leaf width.The main contents and results are as follows:1.The investigation is conducted to the 93 greenbelts of Guangdo ng Province,including four distributions-Pearl River Delta,eastern Guangdong,western Guangdong and northern Guangdong,and 4 categories greenbelts.It is verified that the total Hibiscus plants of Guangdong Province are 11 species,35 types;among whic h are 23 cultivas,3 formas and 1 wild.2.There are 35 Hibiscus plant types in Pearl River Delta which is the most abundant region in Guangdong,while the eastern Guangdong region only appeared in 8.The Hibiscus rosa-sinensis is widely applied in landscape in Hibiscus plants,the frequency is up to 79.6%;the frequency of application of HibiscusSyriacus at least,only 5.4%..The most common application form of Hibiscus is linear planting form,the frequency is up to 65.6%;the film planting form at least,accounted for only 18.3%.In the investigation of the green,The Hibiscus rosa-sinensis and HibiscusSyriacus infection rate of diseases and insect pests were 44.6% and 40% in the greenbelts of investigation.3.The growth performance and flowering amount of Hibiscus are different in different distribution regions.The Hibiscus rosa-sinensis and Hibiscus tiliaceus have stronger growth performance and there are lush flowers in western Guangdong region,but Hibiscus syriacus and Hibiscus mutabilis have stronger growth performance in eastern and northern Guangdong regions.It was established the Hibiscus landscape comprehensive evaluation application model with the 15 indexes,also selected 8 types of the genus of high landscape value from 35 Hibiscus plant types,while Hibiscus rosa-sinensis ‘Yanhong' got the highest score,up to 3.4871 points.4.With cutting seedlings' root tips of Hibiscus schizopetalus,Hibiscus.rosa-sinensis ‘Red'and Hibiscus rosa-sinensis ‘Red lantern' are employed as material.Then using the combination of acidolysis and enzymolysis.Finally,it is successfully identified that the chromosome numbers of Hibiscus schizopetalus,Hibiscus rosa-sinensis 'Red' and Hibiscus rosa-sinensis‘Red lantern' are all 2n=42.5.With diploid Hibiscus schizopetalus as reference sample,flow cytometer is employed to test the ploidy of 32 Hibiscus samples,among which,there are 7 diploids,2 triploids,17 tetraploids,4 pentaploids,1 sextuploid and 1 heptaploid.The corolla d iameter,the mature leaf width and stomatal apparatus size of Hibiscus rosa-sinensis have positive correlation with its chromosome ploidy.The characters of triploid and diploid have no significant difference.It can be found the flower diameter,leaf widt h,the stomatal apparatus length and width of Hibiscusrosa-sinensis cultivas basically increase with the increase of chromosome ploidy.Thus,it can be concluded that the characters of corolla diamater,leaf width and stomatal apparatus size can be used to speculate chromosome ploidy.