| Broomcorn millet (Panicum miliaceum L.), as an important food crop in arid and semi-arid areas, plays an irreplaceable role in agricultural crop structure adjustment and industrial development in China's western. Its nutrient-rich seed with high food value and medicinal value is an important resource for homology of the medical food, so it plays a major role in modern functional food development. Therefore, exploring the procreation and drought resistance of broomcorn millet plants, and improving the output and quality of broomcorn millet, are strategically important enhancing the income of the farmers in producing areas and safeguarding national food regional balance.This research simulation the drought stress, measured shoot length, coleoptile length, radicle length, root dry weight of different broomcorn millet varieties in bud under the drought conditions, and analyzed drought resistance of the 40 broomcorn millet. varieties. At the same time, the relationship between morphological characteristics and physiological-biochemical characteristics and drought resistance in the 10 varieties seedlings were analysed. Moreover, the relationship between content of leaf chlorophyll, SOD, CAT, POD and MDA were observed and their relationship with grain yield were studied after flowering of the broomcorn millet. indicators of drought resistance of broomcorn millet at bud stage, seedling stage, and late growth stage were screen out by grading score and correlation analysis. At last, agronomic traits and yield were analyzed through gray correlation analysis method. The main results were obtained as follows:(1) In the experiment of simulated drought stress of 25% PEG-6000 in bud stage, the results showed that, the correlation coefficient between drought classes of relative germination rate, relative radicle length, relative shoot dry weight, the relative coleoptile length and drought resistance total level 1 were higher and were respectively 0.69,0.68,0.63, 0.60. Therefore, these indexes were regarded as important indicators of drought resistance in bud. The correlation coefficient between drought classes of the relative germ length and relative shoot dry weight and rought resistance total level 1 were 0.55,0.49 respectively, similarly, the relative length of shoot and relative shoot dry weight can be used as indicators of drought resistance in bud stage.(2) In the experiments of the osmotic stress of seedlings, the paper studied some morphological indices of seedlings of the broomcorn millet, measured the seedling survival rate, leaf length, plant height, chlorophyll content, soluble protein content, SOD activity, POD activity, MDA content, O2- content, calculated its drought resistence coefficent and sort the order of the drought resistence by the survival rate. The result showed that, the order of drought resistance is Jichengshu 1, Yi 8422-6-3-5, Ningmi 13, Neimi5, Gu 02-35, Gu 01-391, Yi 8414-1-1-2-1, Gan 9109-6-1-1-1-1-2, Jinmi 4, Gan 9113-1-3-4-1 from big to small, antioxidant enzyme system indicators of the activity of SOD, POD and with leaf length, plant height, chlorophyll, the content of soluble protein and survival rate of broomcorn millet leaves showed significant positive correlation, but the MDA content in leaves of broomcorn millet, O2- content and survival rates were significantly negatively correlated. At the identified seedling stage, relative value of leaf length, plant height, chlorophyll content, soluble protein content, SOD activity, POD activity, MDA content, O2- content can be integrated as the best indicators of drought resistance.3. In the experiment of simulated drought stress in the late growth stage, the trend of chlorophyll content of varieties broomcorn millet is downward, the degradation of chlorophyll is filling slower in the late grain, but decline of chlorophyll Ningmi 13 is smaller, so it have longer leaf function than other two varieties. The SOD activity and CAT activity in leaves of different broomcorn millet varieties have varying degrees of. reduced. Under drought stress, the SOD, CAT activity of Jinmi 4 was lower than other species in the same period, which indicated that drought forces of Jinmi 4 is weak. Under drought stress, with the advance of the growth, the POD activity, and SOD, CAT activity of leaf of different varieties of broomcorn millet were increased and then decreased. Compared the performance of the POD activity and the performance of the content of chlorophyll, it was contrary, which was measured in the same period of in the same leaf position of the different varieties of broomcorn millet. Under the drought conditions, correlation analysis showed that chlorophyll content of broomcorn millet, SOD activity and CAT activity were correalation with broomcorn millet's yield. So they can be initially identified as drought resistance of physiological and biochemical indexes of broomcorn millet in flowering stage.4.1n study the relationship of broomcorn millet yield and agronomic traits, the results that showed the production is most closely grain weight, followed by the number of days of the birth, main stem nodes per plant, grain weight, main spike length, for the final spike weight and plant height. Although the agronomic traits and yield differences of gray related degree, all the differences between the correlation is not very large. |
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