Study On The Difference Of Main Characters Of Rapeseed For Brassica Napus L. In Two Environments With Different Altitude

Oilseed rape is one of the four major oil plants in the world and is one of the most important oil plants in China, too. Because of the taller plant, more exuberant branches and leaves, better qualities of anti-cold and antivirus, better adaptability for fertilizer, higher and stable yield, and higher potential of increasing production, Brassica napus L. is the most important oilseed rape variety that come to be highest economic value.Variety (genotype) is the most important factor which affects yield and quality characters of B. napus L.. However, the ultima formation of yield and qualities is determinate by the effect of genotype, environment and G×E interaction. Environment have a significant effect on B. napus L.. Environment is a general concept, which contains geography, climate, biology, society. And, geography, climate, biology are part of the natural environment, while social environment consists of farming and cropping system, measure of cultivation and supervisory technology, and so on. According to the outside necessary conditions for developing and growth of crops, light, temperature, water, air and nutrition are the basic factor for growth, which are also determinated by geographical place and landform. In order to study the effect on oilseed rape, traditional methods were that study simple effect of a single factor on developing and growth for B. napus L. by way of fixupping other ones. And these valuable studies reported usually had expatiated the basic effect on growth for B. napus L. in detail. However, actually, for crops, environment is a complicated exterior system, whose five basic factors can restrict and affect with each other. In our practical agricultural production, we can rely on the method of controlling the basic factor (light, temperature, water, air) to increase yield and to improve quality distinctly only could come true in the small experiment and examination. If the method was used on large-scale production, the cost would very huge, and would result in lower economic benefit. If we could consider the exterior environment as a organic system with a new conception, we maybe study the environmental synthetical effect on growth of crops. This study would have an important actual benefit for agricultural production.In this article, the author chose the height above sea level as the object which is part of the natural environment and would have especial synthetical effect on growth and some main character of B. napus L.. Different altitudes would result in different light, temperature, water, air and nutrition between different areas. In the condition of having the same geographical place (latitude), different altitudes can result in the especial synthetical effect. For some areas with complicated landforms, it woule be benefit for human to make out oilseed rape planting and help develop oilseed rape production in reason bying study the especial synthetical effect result of height above sea level. Two areas, Beibei and Wanzhou had been chosen as the experiment place, where two F₈ RILs (indicated by "RIL 1" and "RIL 2") had been planted. Five main characters of B. napus L., 1000 seed weight, seedcoat ratio, oil content, protein content and yellow degree of RILs had been measured and analyzed. The results are as follows:1. Bying analyzing the difference of phenotypic value of B. napus L. between two areas with different altitude, it was discovered that oil content was distinctly higher in areas with higher altitude than that in areas with lower altitude, while protein content was distinctly lower in areas with higher altitude than that in areas with lower altitude; Oil content+protein content was distinctly higher in areas with higher altitude than that in areas with lower altitude; Altitude did not have a distinct effect on yellow degree; Altitude could have a distinct effect on seed coat ratio and 1000 seed weight lying on genotype of RIL.2. All five characters displayed continuous variance to different extent, implying that they could be controlled by polygenes. 1000 seeds weight, oil content and protein content fitted for normal distribution and these three characters could be controlled by tiny-effect polygenes, while seedcoat ratio and yellow degree did not fitted for normal distribution and these two characters could be controlled by main-tiny-effect polygenes.3. By and large, correlation coefficients of RILs'main characters were identical in two environments. Negative correlation coefficients of seedcoat ratio and oil content, oil content and protein content, seedcoat ratio and yellow degree, all came up to significance level at 1ï¼…. Positive correlation coefficient of oil content and yellow degree also came up to significance level at 1ï¼…. However, there were some differences in two environments. Firstly, correlation coefficients of the characters in the same RIL were not always identical in two environments; Secondly, between two RiLs, correlation coefficients of the characters were not always identical at the same environment.Bying analyzing the path coefficient of RILs'main characters in two environments, it showed that for seedcoat ratio to oil content, the direct path coefficient was much larger than indirect path coefficient; Direct and indirect path coefficients of 1000 seeds weight to oil content were all quite small; Significance of negative correlation coefficients of protein content and oil content were mainly caused by the direct effect of protein content to oil content; Significance of positive correlation coefficients of yellow degree and oil content were mainly caused by the indirect effect of yellow degree to oil content by way of seedcoat ratio, so higher yellow degree could result in higher oil content by the effect of seedcoat ratio.4. Bying drawing graphs and analyzing correlation coefficients to conjecture the G×E interaction, it was discovered that 1000 seeds weight and yellow degree had negative G×E interaction, while seedcoat ratio, oil content and protein content had positive G×E interaction; The G×E interaction of seedcoat ratio, yellow degree and oil content may be smaller, while the G×E interaction of 1000 seeds weight and protein content may be greater.5. The general index of characters for B. napus L. in two environments showed distinct difference that had come up to significance level at 1ï¼…. The general index of characters for B. napus L. was higher in the areas with higher altitude than that in the areas with lower altitude, indicating that the commercial value of B. napus L. planted in the areas with higher altitude was higher than that in the areas with lower altitude.