Effects Of Environmental Factors On The Growth And Development Of Paulownia Seedlings

In order to improve the quality of Paulownia seedlings breeding and accelerate the breeding process of seedlings,the effects of temperature and day length on the growth and development of Paulownia were studied by using(Paulownia fortunei(Seem.)Hesml.)seedlings and buried seedlings.The 18 combinations of the cutting methods of tender cuttings(terminal buds and without terminal buds)and were carried out with a five-year-old‘Paulownia tomentosa × P.fortunei 33’ as the experimental material under shading conditions.The effect of photoperiod on the tissue culture of Paulownia was studied by using the 12 clones of Paulownia sinensis as the experimental material.The results showed that:(1)There is a difference in growth and development between the root bud and the top bud of the seedling under the control of temperature and day length.With the increase of temperature and the extension of sunshine time,the shoot buds of the seedlings are more likely to survive and achieve continuous growth,and the lateral buds can form flower buds in advance.Although the top buds of the rooted shoots can survive but grow slowly,the lateral buds cannot form flower buds in advance.Under the condition of 30℃/25℃for 24 h,the bud bud can achieve continuous growth.The base diameter stops growing for a longer period of time.There were photosynthetic‘lunch breaks’ in the Paulownia seedlings in July,August and September,and the photosynthesis rate of Paulownia seedlings decreased under the24 h sunshine length.(2)According to the above,the best concentration of ABT rooting powder is400 mg·L-1 for 5s when the tender branch cutting with terminal bud is utilized to cultivat the seedlings.(3)The growth of buds was the best under the condition of light for 16 h and medium MS+6-BA(4.0 mg/L)+NAA(0.1 mg/L).When the illumination time is less than 16 h,the proliferation rate increases with the increase of illumination time.When the illumination time exceeds 16 h,the proliferation rate decreases with the increase of illumination time.Hybrid Paulownia 12 excellent clones were used as explants.Hybrid Paulownia 12 hydroponic buds were used as explants,and the root induction effect was best under the condition of light for 16 h and medium 1/2 MS+NAA(0.3mg/L).