Study On Biological Characteristic And Chromosome Number And Karyotype Of Coreopsis Tinctoria

Coreopsis tinctoria belonged to the composite family Coreopsis Linnherb, most research focused on chemical composition and medicinal value, but the study on biological characters and karyotype was still blank.In this study, the plant of C.tinctoria cultivated in the experiment base of Xinjiang Agricultural University was used as the research object.Investigation and research from the aspect of C.tinctoria growth dynamics, photosynthetic characteristics, flowering phenology, breeding system, pollination biology, seed drought characteristics and chromosome karyotype etc., specific research results were as followed:(1) The Study through growth dynamics of the C.tinctoria growthvigor, and indicated that the C.tinctoria plant growth pattern was slow-fast-slow, which belonged to the "S" type growth curve.(2) The adaptability of the C.tinctoria leaves to the weak light and strong light was stronger, but the absorption efficiency of the light energy was low; Pn showed a bimoda curve, and C.tinctoria leaves appeared “Photosynthetic midday depression” at noon,C.tinctoria the diurnal change of Pn influence factor of the maximum Gs.(3) C.tinctoria florescence mainly concentrated in July and August, tubular flower was bisexual flowers, the corolla lobes, and the corolla tube, the corolla path, synantherous stamens, ovary, stigma and style grouped etc.; The flowering process of C.tinctoria capitulum had five stages, tubular flower bloom dynamics is divided into seven stages and each stage have obvious characteristics of identification.(4) C.tinctoria pollen grains prolate was long ball shape, very concept of three lobed circular, equatorial plane near elliptic, with tricolporate, rough surface, with clear spiny ornamentations; After screening, The best recipe for liquid culture medium of C.tinctoria pollen germination medium was ME3+ sucrose 100 g/L+PEG-4000 200 g/L, the cultivate temperature was 25?, training time in 2 or more than 2 hours; Through detection of different staining methods considered that the highest value of pollen vitality of C.tinctoria flowers was after pollen about 6 h. The conclusions of OCI, P/O ratio and bagging experiment were basically the same, so the C.tinctoria belonged to a mixed mating system. The main pollinators of C.tinctoria was Syrphidae insects and Apis mellifera Linnaeua(5) Seed biology research showed that C.tinctoria seed individual small, optimal germination temperature was 25?. In conditions of PEG-6000 simulated drought, experimental resulte showed that mild drought was good to C.tinctoria seed germination and seedling growth, moderate or severe drought inhibited the seed germination and seedling growth and seed complex germination recovery strong, neat degree higher, making it adapt to survive in the arid area.(6) C.tinctoria is a kind of diploid plants. The karyotype formula of C.tinctoria is 2n=24=14 m+10 sm; and relative length of chromosome composition is 2n=24=8 M2+12 M1+4 S; The longest chromosome to the shortest length ratio of C.tinctoria was 1.747:1, and the ratio of 3 pairs of chromosome arm among them was greater than 2 which was 25% of the whole chromosome. The asymmetrical karyotype coefficient was 62.31%, the karyotype of C.tinctoriawas 2 A type.