Ornamental Evaluation And Pollen Characteristics Of Modern Rose

Modern rose were a group of hybrid variety bred by repeated hybridization and long-term selection among species in Rosa,which had high ornamental value.However,in most areas of our province,the goal of modern rose breeding was still vague,and the research on breeding theory was still insufficient,which made the quantity and quality of new varieties selected by modern rose lower than those of domestic counterparts.Therefore,the comprehensive evaluation of ornamental value and pollen characteristics of modern rose were carried out in this thesis,in order to provide theoretical basis for modern rose cross breeding.The major findings were as follow.First of all,the comprehensive evaluation model of modern rose ornamental was constructed.It was determined that the flower type,group flowering period and flower diameter were the main factors affecting the ornamental evaluation of modern rose.Eleven varieties with high ornamental value were screened out from 34 varieties of modern rose cultivated in eastern Anhui,including 2 first-class varieties and 9 second-class varieties.The results showed that the main ornamental characters of modern rose were rich in genetic diversity,and the average coefficient of variation reached 0.493.The above results could provide theoretical basis for modern rose breeding objectives,variety evaluation and landscape application.Secondly,the vitality of modern rose pollen was discussed.Pollen culture in vitro was the first choice to determine the activity of modern rose powder.The best medium formula was 150 g L Sugar+0.20 g·L-1 H₃BO₃+0.20 g·L-1 Mg SO₄·7 H₂O,and I₂-KI staining method was more suitable for rapid determination of the vitality of modern rose pollen.The pollen viability of modern rose on the day of flowering was higher than that before and after flowering,so the time of collecting pollen could be chosen according to the needs of cross breeding.After pollen was collected,it could be preserved by low-temperature drying.In this study,it was found that modern rose powder can be effectively preserved for about 40 days under the drying conditions of-18℃and-80℃.In addition,among the 34modern rose varieties tested 5 varieties with pollen vitality exceeding 30%,accounting for14.7%,which could be given priority as male parent materials when selecting hybrid parents.At last,the physiological and biochemical characteristics of pollen abortion of’Shining Rigina’were analyzed.The number of petals in’Shining Rigina’was large and the frequency of stamen petalization was high.Anthers were few in number,pale in color and withered.At the same development stage,the content of’Pro in’Shining Rijina’was lower than that in’Knockout’,and the content of MDA was higher.And the activity of active oxygen scavenging enzyme was unstable in’Shining Rijina’.It was speculated that the imbalance of reactive oxygen species in the anther of’Shining Rigina’led to excessive accumulation of MDA,and the low Pro content led to insufficient nutrition,which jointly led to the pollen abortion of the anthers of’Shining Rigina’.