| Rapeseed is one of the three major oil crops in the world.In addition to oil use,rapeseed also has good ornamental value.In recent years,some rape breeders in China have taken the lead in breeding coloured rapeseed,and the selection and promotion of coloured rape strains has enriched the flower colour of rapeseed,improved the ornamental nature of rapeseed and promoted leisure tourism and rural tourism,but less research has been carried out in relation to coloured rapeseed.The present study investigated the physiological mechanisms of senescence,the preservation of cut rape flowers and the flower-visiting behaviour of bees on coloured rape.The specific findings of the study are as follows.(1)Twenty different flower colours of kale type rapeseed were classified into four colour families: yellow,orange,white and red based on visual observation.11 of the 20 different coloured rapeseed flowers showed a significant increase in anthocyanin content during senescence,accounting for 55% of the total,with the greatest increase being in two rapeseed lines of the yellow family,with increases of 88.3% and 72.6% respectively;during senescence of rapeseed flowers,the petal surface The principal component analysis of the 13 colour indicators showed that the 20 fresh and senescent flower colours could be divided into three groups: yellow-orange,red and white flower colours,with the yellow-orange flower colour having the highest yellowness value of b* and the lowest redness value of a*,the red flower colour having the lowest yellowness value of b* and the highest redness value of a*.The white colours have the highest brightness values.The total chlorophyll content of the four typical flower colour varieties,Anhui Oil 50(yellow flower),Anhui Orange 1(orange flower),Anhui White 1(white flower)and Anhui Red 1(red flower),decreased significantly during senescence,except for Anhui Red 1;the soluble sugar content decreased significantly.The metabolome analysis of the four typical flower colours identified a total of eight anthocyanins and showed significant differences between flower colours.The four flower colours of rapeseed flowers had extremely low levels of delphinidin and mallow pigments,which may be the main reason for the difficulty in blue and purple rapeseed flowers.(2)Compared with the distilled water control,the rate of change of flower stems in the Life of Flowers treatment was significantly lower than that of the control from day 5 of bottling,and the decrease in water balance,fresh weight reduction rate and electrical conductivity in the Life of Flowers treatment was significantly lower than that of the control from day 2 of bottling;of the three preservatives,Coriolis,Life of Flowers and Life of Flowers,Life of Flowers significantly extended the bottling life of cut rape flowers to day 7,and rape flowers,especially coloured rape flowers,can be used as fresh cut flowers.used in the development of rape sea tourism products,and Flower Life can be used as a preservative for rape cut flowers.(3)Under field environmental conditions,bees showed a preference for yellow rapeseed flowers,showing that the number of visits to yellow rapeseed flowers was significantly higher than the number of visits to other coloured flowers at the same time,with no significant difference between the number of visits to orange,red and white flowers by bees.On sunny mornings,the number of bee visits to yellow and white newly opened pollen-returned pollen flowers was significantly higher than the number of visits to non-pollen flowers without pollen return,but for orange and red canola flowers,there was no significant difference between the number of bee visits to pollen-returned and non-pollen flowers,while on sunny afternoons,the number of bee visits to all four flower colours was significantly higher than the number of visits to non-pollen flowers with or without pollen return,while on sunny afternoons,the number of bee visits to yellow and white canola flowers with or without pollen return was significantly higher than the number of bee visits to yellow and white flowers with or without pollen return.There was no significant difference in the number of flower visits between pollen and non-pollen flowers for all four flower colours on sunny afternoons. |
