Effect of ^(12)C^(6+) Ions Beam Irradiation on Seed Germination and Enzymes Activity in Seedlings of Sweet Sorghum

[ Objective] The aim was to study the effect of 12C6 ＋ ions beam irradiation to two varieties of sweet sorghum on seed germination and some enzymes activity in seedlings with different doses, and provided a theoretical foundation for sweet sorghum breeding. [ Method] After germination, the germination potential, germination fraction and enzyme activity were detected, respectively. [ Result] The results showed that with the dose increased, the germination potential of sweet sorghum increased first and then decreased, while their germination fraction presented ＂shoulder like shape＂ ; the activity of LDH, SOD, CAT and GSH-Px increased first and then decreased with doses, they presented slight differences among different enzymes. [ Conclusion] Low dose radiation could accelerate germination of sweet sorghum seeds and enzyme activity could remain at a relatively high level. Enzyme activity decreased with high doses and the growth of sweet sorghum was inhibited.

Effects of Magnetized Water on Seed Germination of Welsh Onion (Allium fistulosum L.)

With Welsh Onion seeds employed as materials, effects of magnetized water on seed Germination were studied. The results showed the treatment of magnetized water soaking for 4 h promoted water absorption rate and amylase ac- tivities of seeds significantly, which accelerated the transformation process of en- dosperm starch to soluble sugar, resulting in emergence of 36 hours in advance under low temperature condition. Germination rate and germination potential of magnetized water soaking were higher than the contrast by 6.7% and 10.0%, which helped cultivate vigorous seedling.

Application Effects of Ultra-fine Powder Shaped Maize Seed Coating Agent in Spring Sowing areas in northeast China

The research explored adaptability maize seed coating agent in spring sowing and effects of ultra-fine powder shaped areas in northeast China. The results showed that germination potential and rate both improved around 5% and the num- ber of root increased by 4% in the treatments with ultra-fine powder shaped maize seed coating agent compared with the control group without seed coating. What＇s more, the treatments with ultra-fine powder shaped maize seed coating agent took advantages in terms of fresh weight of seeding, stem diameter, and dry weight. It is notable that control effects on underground insects performed the best, with per- centage over 94%, which is more excellent relative to other agents in markets. Therefore, ultra-fine powder shaped maize seed coating agent can be widely applied in spring sowing areas in northeast China, without side effects.

Autotoxicity of Phthalate Esters in Tobacco Root Exudates:Effects on Seed Germination and Seedling Growth

Autotoxicity is one of the major factors that impede continuous cropping.It is defined as the toxic influence of chemicals released from one plant species on the germination and growth of individuals of the same species.Here, in order to exam the autotoxicity of tobacco root exudates, root exudates were collected from tobacco plants grown both in cultural solution and on natural soil.Using ultraperformance liquid chromatography coupled with triple-quadrupole tandem mass spectrometry, main autotoxic chemical substances in the root exudates were identified.The autotoxic effects of suspected autotoxins on seed germination(including germination rate,germination potential, germination index, and vigor index) and seedling growth were analyzed.Dibutyl phthalate(or diisobutyl phthalate), dioctyl phthalate, and diisooctyl phthalate were identified in tobacco root exudates.It was observed that high concentrations(greater than 0.5 mmol L^(-1)) of each identified phthalate ester caused significant(P < 0.05) inhibition of tobacco seed germination and seedling growth.It can be concluded that phthalate esters such as dibutyl phthalate, diisobutyl phthalate, and diisooctyl phthalate in tobacco root exudates may play an important role in tobacco autotoxicity.