Reproductive Characteristics And Breeding And Cultivation Technologies Of Polygonatum Cyrtonema

Polygonatum cyrtonema is one of the original plants included in the Chinese pharmacopoeia in 2015.It has smooth property,tastes sweet,belongs to channel tropism of spleen,lung,and kidney,has the effect of invigorating qi,raising Yin,strengthening spleen,moistening lung,benefiting kidney.Under the background of health industry,Polygonatum industry has entered a new period of rapid development,while wild resources can no longer meet the market's demands.The supply of high-quality seeds has become the bottleneck in the production of fine seedlings and high-quality medicinal materials.This study focuses on the key technologies of reproductive biology,breeding and cultivation technologies and fruit-setting characteristics.The main results are as follows:(1)The reproductive biological characteristics of P.cyrtonema were clarified.Seedlings begin to emerge from mid-March to early April,while flower bud differentiation was completed before seedling emergence,and inflorescences were formed before leaf spreading.Blooming stages gradually begin in mid-late April,and from the end of April to mid-May turns into late flowering stage,with the flowering stage ranging from 36 to 45 days.The flowers of P.cyrtonema bloom from the base of the inflorescence axis to the top,usually 4 to 22 inflorescence,each inflorescence(2 to)4 to 10(to 21)flowers,individual flower period 26?38 d.It takes about 20 to 25 days for a single flower from bud to bloom,after pollination about 2 days,the perianth withers,ovary gradually expanded,if not pollinated,it would continue to bloom for 3 to 5 days,and then wither.Inflorescences were formed before leaf spreading and the nutrients were provided by rhizome.On the first day of blooming,the pollen activity was the highest when the anthers gathered around the stigma,and the stigma was the strongest when the stigma extended out of the perianth and secreted mucus.The phenology of flowering of P.cyrtonema among different germplasm is obviously different.(2)The effects of rhizome size on the growth and development of P.cyrtonema was revealed.flowers and leaves of P.cyrtonema open at the same time,flowering and fruiting of the main nutrients from the rhizome.No matter the size of rhizome,the flowering and fruiting of P.cyrtonema is mainly dependent on polysaccharides and other substances of the second age section.If the rhizome is too small,it is difficult to support P.cyrtonema flower and bear fruit.the blooming and fruiting conditions of the large rhizome P.cyrtonema were significantly better than the small rhizomes of P.cyrtonema Nutrient transport firstly satisfies the base flowering and fruiting,so the number of fruit sets and the single seed weight decrease from the base of the plant to the top gradually.Therefore,the large size rhizome of P.cyrtonema should be uesd for seed production.The distribution of fruit-setting resources could be optimized by removing the tops and buds of P.cyrtonema.(3)Effects of planting depth and environment on the growth and development of P.cyrtonema.Planting depth significantly affects seedling emergence and growth:under the planting depth of 5 cm and 10 cm,the seedlings of P.cyrtonema could emerge normally,while the planting depth of 15cm could easily lead to root death and low seedling emergence rate,and its plant height and stem diameter were significantly lower than those of the 5 cm and 10 cm groups.P.cyrtonema is self-sterile and largely depends on insect pollination.The seed setting rate of P.cyrtonema was higher in open planting,but the stalk can be inverted before the seeds ripen,so moderate shade on P.cyrtonema is beneficial to the harvest of mature seeds.Therefore,the seed orchard should not be built in a place with anti-pest facilities,but should also be properly shaded.