Effect Of Different Light,Sowing Rate And Root Temperature On Growth And Developmeng Of Rice Seedlings

Rice is one of the major food crops,mechanized planting rice production mechanization of the most critical technical means.Realize the mechanization of rice planting,seeding machine dedicated plug seedling tray is the key,the seedling quality directly affects the quality of mechanical transplanting rice.Because Southern rice seedling period,cloudy and rainy weather occurs frequently,is likely to cause surface soil temperature is low,the light is weak,which is not conducive to the normal growth of rice seedlings,and severe cases may affect the time and quality of rice machine plugged in,and ultimately affect rice yield.Therefore,changing the existing farmers seedling greenhouse model to develop an artificial regulation of growth environment,improve seedling tray seedling quality and scale seedling production of new models to promote basic way seedling rice seedling production standardization,security,industrial development.The use of artificial light type closed plant rice seedling plant technology clear relationship between development and environmental factors,can effectively regulate the growth and quality of seedlings under artificial light rice seedlings in a controlled environment.For this reason,under artificial light paper closed plant factory in artificial light controlled environment explores light environment,sowing rate and root temperature on the growth and development of rice seedlings.Conventional varieties of rice as a test material,artificial light with LED for closed plant factory to control the temperature of 28±1 ℃,relative humidity of 70±5%,CO₂ concentration of 550 umol mol^-1 under environmental conditions,has set up spectral,light intensity,sowing rate and root temperature test.Main research results were as follows:1.The first test was tested to investigate the effects of light intensity on rice seedling growth,biomass and growth and metabolism.The results showed that the seedlings of plant height,biomass,seedling index,root activity increased with the increase of the light intensity;chlorophyll content with the increase of the light intensity decreases;seedling fresh weight,dry weight,with the net photosynthetic rate the light intensity was increased after the first increase in a decreasing trend;net photosynthetic rate of seedlings and soluble sugar,soluble protein content was positively correlated.The results suggested under the light intensity of 320 μmol m^-2 s^-1 complex spectrum of red and blue LED robust seedling growth and biomass accumulation more rice factory seedlings suitable light intensity.2.On the basis of the preferred density LED light on this test to further explore the effects of LED spectrum of rice seedling growth.The results showed that the plant height,leaf area,fresh weight,dry weight,soluble sugar and soluble protein of LED light treatment were greater than those of CK treatment.The plant height,shoot fresh weight,and SOD activity in the 1R₁B treatment were significantly less than those of the 2R₁B treatment.on the basis of 2R₁B,the treatments after adding short-wave red light or green light,stem diameter,leaf area,the number of white roots,dry weight,SOD,APX,GR activity of the both treatments were greater than those of the 2R₁B treatment.The fresh weight,dry weight,soluble protein and other indicators in R₁BR2 treatment were more than those of R₁BR₂G treatment.The results suggested the rice seedlings preferred to red light,and adding shortwave red light or green light was benefit to accumulation more biomass,growth of rice seedling.3.Based on the preferred combination of spectral energy LED light source,this paper discusses the effects of different sowing of rice seedlings sowing growth.The results showed that stem diameter,leaf area,root activity,chlorophyll content and net photosynthetic rate of seedling with increasing seeding rate,showed a downward trend,is not suitable for sowing rice seedlings excessive population growth.The results suggested transplanting seedlings sowing rate to 80 g/plate is more suitable,large seedling leaf area,high root activity,accumulated more biomass,group performance,and is conducive mechanized rice planting.4.On the basis of a preferred LED spectral energy distribution and broadcast on the sowing,to explore the effects of temperature on rice seedling root growth.The results show that with the increase of root temperature was better than control,seedling stem diameter,leaf area,root vigor,chlorophyll content and net photosynthetic rate and other indicators are increase first after declining trend.28 ℃ treatment combination index was significantly greater than 24 ℃,but there was no significant difference with 32 ℃.28 ℃ with the highest root activity,32 ℃ processing times.32 ℃,24 ℃ treatment of net photosynthetic rate was significantly less than 28 ℃,but no significant differences between treatment.The results suggested the suitable temperature is 28 ℃ for rice seedlings,seedling root activity is high,strong seedling index is large,the biomass accumulation,more favorable cultivating strong seedling.In summary,the rice seedlings under artificial light factory controlled environment suitable spectrum is red and blue light red complex(R₆₃₀BR₆₆₀),light intensity was 320μmol m^-2 s^-1,sowing rate 80 g/plate and root temperature of 28 ℃.The use of environmental control technologies closed plant artificial light will effectively regulate plant growth and development of seedlings and seedling in rice seedling cultivation factory.