Study On Pollination Characteristics Of Artemisia Ordosica

Artemisia ordosica is mainly distributed in the mobile and semi-mobile sand dunes of desert and semi-desert below 1500 m elevation in China.Artemisia ordosica,a semi-shrub of Artemisia ordosica.Compositae is a pioneer plant for wind-break and sand-fixation.In1958,the Shaanxi Province of Yulin began to plant trees by air,dropping seeds of Artemisia ordosica on a large scale.Aerial seeding has played a positive role in the ecological environment of Yulin,but with the large-scale planting of Artemisia ordosica,pollen allergic diseases began to appear.The results of this experiment are as follows:(1)Some plants of Artemisia ordosica appeared buds on June 28,a cluster of flowering plants appeared on July 28,and entered the last flowering period on August 13,most of the flowers are already in bloom.At the level of secondary inflorescence branches,the flower heads open first from near the base,and the inflorescence branches open for4-12 days.The flower heads lasted 4-6 days,and most of the individual flowers lasted only1 day.2-6 marginal female flowers,4-14 central bisexual florets.The head is not more than 2.21 mm in diameter.The florets open first from the edge of the female flower,most of the single flower after 1d Yan Yan,and then a new round of single flowers continue to open,from this cycle until all the single flowers in the head to open.(2)The observation of the growth indexes of Artemisia ordosica shows that all the growth indexes of Artemisia ordosica are correlated with each other in the growth process,and each growth index has a significant positive correlation.(3)The pollen grain of Artemisia ordosica is single,the outline of the pollen grain is small wave shape,and has obvious dimorphism.One is nearly spherical in Size: 23.51 μm(20.10 ～ 24.91)16.99μm(15.81 ～ 17.32)with P/E = 1.38;the other is spherical in Size:17.66 μm(16.11 ～ 18.43)17.10 μm(15.99 ～ 18.01)with P/E= 1.03.The pollen grain surface was spiny-granular compound ornamentation with 3-hole furrow.(4)The pollen concentration of Artemisia ordosica was the highest at 12:00,the sum of the low and high pollen samplers was 768,and the lowest at 3:00 was 24 hours,a total of 43 pollen grains were collected from Artemisia ordosica by low pollen sampler and high pollen sampler.Within 24 hours,the pollination efficiency of Artemisia ordosica was significantly positively correlated with temperature(P <0.01),Wind Speed(P<0.05)and relative Humidity(P <0.05).