Application Of Nanomaterials In Production Of Violaceus Artificial Seed

Artificial seed technology is an extension of plant tissue culture technology,which is important for rapid propagation of crops, saving endangered species,maintaining good traits, improving seed adaptability and so on. Selections of manmade seed coat materials and additives decide seed characteristics and directly related to the suitability of seed germination and rooting. Therefore, the study of manmade seed coat material has been a hot topic of artificial seed technology.Take violaceus（Orychophragmus violaceys） for the study, add nano-SiO₂ and nano-TiO₂ into seed coat and make double-embedded artificial seeds. Study nanomaterials’ effects to water retention, mechanical strength and antimicrobial capacity of manmade seed coat; study nanomaterials’ effects to germination rate,rooting rate, speed of rooting and germination of artificial seed. Select a very production method of manmade seed coat who has the best germination and rooting rate in sterile environment, and provide a method to adjust mechanical properties.Specific results are as follows:（1）Effects of nano-SiO₂ and nano-TiO₂ to water retention capacity of manmade seed coat were studied and the results shows: Nano-SiO₂ and nano-TiO₂ reduced the moisture content and rehydration rate of alginate capsules, effect of nano-TiO₂ to capsule moisture content reached a significant level, rehydration rate reached a very significant level, effect of nano-SiO₂ to rehydration rate reached a significant level.Excessive adding of two kinds of nano materials will weaken the water retention capacity of sodium alginate, and it is not conducive to artificial seed storage.（2） Effects of nano-SiO₂ and nano-TiO₂ to mechanical properties of manmade seed coat were studied and the results shows: Content of nano-TiO₂ content and hardness of the capsule showed a linear relationship, with nano-TiO₂ concentration increasing, capsule’s hardness, resilience and decline and water-soluble adhesive consistency decrease; Linear relationship between nano-SiO₂ content and capsule hardness is not obvious, with nano-SiO₂ concentration decreasing, capsule’s hardness,resilience and decline and water-soluble adhesive consistency increase. It provided a method to adjust mechanical properties of manmade seed coat, nano-SiO₂: nano TiO₂= 0.5: 1 can relieve the weaken of nano-TiO₂ to manmade seed coat hardness and resilience ed.（3）Auxin effect of nano-TiO₂ to artificial seeds was studied and the results shows:Nano-TiO₂ and NAA have a similar effect of auxin, only added 30 g / L nano-TiO₂ as auxin, violaceus artificial seed germination rate reached 87.5%, rooting rate reached37.5%. Nano-TiO₂ can enhance artificial seed germination and rooting speed, the experimental group only containing nano-TiO₂ average speed of germination is 3.25 d faster and rooting fast 2d than the experimental group only containing NAA.Single-embedded artificial seeds 30 g / L Nano TiO₂+0.1mg / L NAA has the best germination results, the germination reached 100%, the rooting reached 80%.（4） Antibacterial capacity of nano-TiO₂ to artificial seeds was studied and the results shows: 30 g / L TiO₂ can make a single layer embedded violaceus artificial seed15 d germination rate reaching 83.33%, 15 d contamination rate reaching 5.6%, 30 d contamination rate reaching 30.6%.（5）Two-layer embedded violaceus artificial seeds was made, content of the inner and outer seed coat nano material, nutrients and growth hormone were adjusted, the results shows: Endotesta formulation is 6% S.A + 15 g / L TiO₂ + 0.25 mg / L NAA + 1/ 2MS + 30 g / L sucrose, testa formulation is 7% S.A + 30 g / L TiO₂ + 15 g / L SiO₂ recipe can make seeds’ germination rate reach 91.7% rooting rate reach 75% in unsterile environment. Experiment has reached a way of making artificial seeds who can germinate and root in unsterile environment.