Study On Botany Features And Seed Germination Characteristics Of Matthiola Superba

Matthiola resources are scarce in our country and the classification is still controversial.Matthiola superba is a wild plant only distributed in the desert in northwestern Xinjiang,China.M.superba is a highly potential resistant breeding resource.This study observed and described its botanical characteristics through field investigation and indoor observation,in order to provide a basis for the classification of Matthiola,and the common cultivated M.incana in China was used as the the control species,so as to understand the the effects of environmental factors such as temperature,light,soil water content,sand burial depth,salt stress and drought stress on seed germination of two species of Matthiola,to explore the ecological adaptation mechanism of M.superba and lay a foundation for its development and utilization as garden ornamental plants.The main research results are as follows:（1）M.superba is a perennial herbaceous plant with white hairs.Its leaf margin is irregularly serrated or lobed,raceme,aromatic at night,petals roll outward;and nocturnal aroma;the epidermis on the leaves has stomata distribution and the cells are polygonal;the seeds produced mucilage when imbibed in water;pollen grains are spherical,with 3 grooves,and the groove is up to two poles;and the karyotype formula for chromosomes is K（2 n）=2 x=12=8 m+2 sm+2 st.（2）Two species of Matthiola seeds could germinate within 5℃～30℃,but the temperature diurnal range promoted germination of two species of Matthiola seeds.The optimum germination temperature of M.superba seeds were 15/25℃and 20/30℃,while the optimum germination temperature of M.incana seeds were 10/20℃and 15/25℃,continuous darkness or semi-light/semi-dark promoted seeds germination of two species of Matthiola,the optimal soil water content for germination of M.superba seeds were 20%～25%,and optimal soil water content for germination of M.incana seeds were 15%～20%,the suitable depth for seeding emergence of M.superba seeds were 0～1 cm,and M.incana seeds were not resistant to sand burial.Under the same salt concentration,the germination rate and germination index of M.superba were lower than M.incana,but M.superba could enter dormancy under high salt stress,and had higher recovery germination rate after stress relief.Different types of salt solution on two species of Matthiola seeds germination inhibition strength is:Na₂CO₃>Na HCO₃>mixed salt>Na₂SO₄>Na Cl;the recovery germination experiment showed that osmotic stress was the main factor to inhibit the germination of M.superba seeds,and high concentration of salt stress showed certain ion toxicity.The two species of Matthiola seeds had certain drought tolerance at germination stage.The results showed that the wild Matthiola distributed in the northwestern part of Xinjiang conform to the description of the botanical characters of M.superba,and their seeds produced mucilage when imbibed in water,the seed germination is resistant to high temperature,the soil water content is widely adapted,the shallow sand burial is resistant,and high seed dormancy rate,which were the low risk adaptation strategy to harsh and changeable desert ecological environment.Compared with M.incana,which are suitable for low-temperature periodic germination,narrow adaptation to substrate water content,intolerant of sand burial,and low seed dormancy rate,M.superba is more suitable for landscaping in Xinjiang.