| Armeniaca sibirica var.pleniflora is an indigenous tree species growing in the western region of Liaoning Province.The flower is double-petaled in pink color,with its shape similar to that of Armeniaca mume.It is of high ornamental value and can serve as a good ornamental tree species for landscaping.In this paper,the author studies the population variation of Armeniaca sibirica var.pleniflora by observing its phenological period and phenotypic character,looks into its gametogenesis process by carrying out researches on pollination methods,pollen viability and crossbreeding,and attempts to solve the technical issues on its gametogenesis and agametogenesis by studying the seed treatment,seedling raising,and grafting techniques of Armeniaca sibirica var.pleniflora.This paper lays a theoretical foundation for the selection,breeding and reproduction of Armeniaca sibirica var.pleniflora,provides new plant materials for gardens in the northern part of China,and has great economic,ecological and social significance.The research results of the paper are as follows:(1)The flowering period of Armeniaca sibirica var.pleniflora is early April.The flowering period generally lasts from 15 to 18 days.The higher the temperature is,the earlier the flowers come out,and the shorter the flowering period would last.The end of the flowering period,leafing period,and fruit setting period are almost concurrent.(2)The maximum variation coefficient of fruit yield per plant of Armeniaca sibirica var.pleniflora is 0.95.The variation coefficient of petal numbers and flower diameter is small.The shape of its leaves are mostly oval,with acuminate tips and hairy on both sides.Its flowers are double-petaled and the majority of the flowers are of pink color.Its fruits are mainly oblate,with rich colors and little juice in the pulp.The fruits have a sour taste and most of them are dehiscent;the pulp and the kernel are loosely attached and the seed has a bitter taste.Among the flowers of Armeniaca sibirica var.pleniflora,flowers with double pistils,abortive pistil,and single pistil account for 67.7%,15.9%,and 16.4% of the total,respectively.(3)The author selects the most suitable culture medium for pollen germination of Armeniaca sibirica var.pleniflora: sucrose 10g/100ml+boric acid 0.01g/100ml+calcium nitrate 0.025g/100ml+agar 0.8g/100 ml.The p H value of the medium is 6.0.The initial pollen germination rate measured in this culture medium is 90.34%,showing significant difference between the pollen germination rate of individual plants.The pollen viability of Armeniaca sibirica var.pleniflora gradually drops with the extension of storage time.The lower thestorage temperature is,the slower the pollen viability would drop.The storage result of Armeniaca sibirica var.pleniflora pollen was better at-80 ℃ and-20 ℃,with pollen germination rate reaching respectively 85.57% and 76.54% when stored for one year.(4)Armeniaca sibirica var.pleniflora is self-incompatible.It mainly depends on entomophilous pollination and wind pollination.The fruit setting rate in the cross pollination from different individual plants of Armeniaca sibirica var.pleniflora to the same plant of Armeniaca sibirica :29.67%,rate in the cross pollination rate from different individual plants of Armeniaca sibirica var.pleniflora to the same plant of Armeniaca sibirica var.pleniflora:11.33%.The fruit setting rate in the cross pollination from the same plant of Armeniaca sibirica to different individual plants of Armeniaca sibirica var.pleniflora : 9.75%.(5)The direct sowing method in autumn has proven a good method for seed treatment.The period of seedling emergence is late April,with the seedling rate at 94%.The basal diameter growth and height of the seedling are 4.78 mm and 54.19 cm,respectively.The method of side grating has achieved fairly good effect when grafting Armeniaca sibirica var.pleniflora to Armeniaca sibirica of 1-year-old.The survival rate of side grafting is 90.2%,with the preservation rate at 87.4%,branch length growth at 99.26 cm,and branch thickness growth at 0.85 cm.(6)The most important factor that affects the effect of high-branch grafting of Armeniaca sibirica var.pleniflora to Armeniaca sibirica is the grafting time,while the grafting method and age of the rootstock have only minor influence.The most ideal time for high-branch grafting of Armeniaca sibirica var.pleniflora to Armeniaca sibirica is early April. |
