The Effects Of Lodging Resistance Of Oilseed Flax On Genotype And Planting Density

Employing three oilseed flax varieties with different lodging resistance and settingdifferent planting densities, the relationship between the morphological characteristics,physicochemical properties, especially lignin biosynthesis enzymes of oilseed flaxculm and its lodging resistance was systematically studied. The variety difference inoilseed flax culm with different lodging resistance was analyzed. Moreover, theinfluence of the planting densities on lodging resistance of oilseed flax. In details, themain results are summarized as follows:1. Compared with the oilseed flax with poor lodging resistance (dingya23), the heightand the height of center of gravity of the oilseed flax with strong lodging resistancereduced obviously, while the stem diameter and wall thickness increased. The relatedanalysis indicated that the there is a negative correlation between oilseed flax actuallodging ratio and the stem diameter as well as wall thickness, and a positivecorrelation between oilseed flax actual lodging ratio and the height and the height ofcenter of gravity. In the actual production process of the oilseed flax, the higher height,lower height of center of gravity, thicker stem diameter and wall thickness areembodiments of strong lodging resistance of oilseed flax.2. The physiological and biochemical characteristic of the oilseed flax culm iscorrelated with the lodging resistance.There is a noticeable discrepancy in lignincontent of different oilseed flax varieties. However, compared with the change oflignin content, the cellulose content of oilseed flax culm has a steady change. Thevariety with strong fracture resistance and small lodging index has a high lignincontent and powerful activity of PAL, CAD, CoA,4CL and TAL. The related analysisindicated that, there is a positive correlation between lignin content and fractureresistance(r=0.958, P<0.05) as well as the activities of PAL, TAL, CAD(r=0.886,0.902,0.969, P<0.05), while there is a insignificant positive correlation betweenlignin content and the activity of4CL(r=0.964, P>0.05). The lignin content can beregard as a crucial factor in lodging resistance.3. Under the different oilseed flax planting density,the influence of lodging area ofdifferent oilseed flax varieties is large. there is a significant negative correlationbetween The lodging rate and yield of the field. A lodging large area will reduce the yield. With low planting density, the variety with strong fracture resistance has highgrain weight per plant and number of capsules,the unfilled grains is low and the yieldis best.But when planting density is too high,the lodging area is increasing, thenumber of stems of plants and grain weight is reducing. Moreover, the variety withmedium fracture resistance is moer stable.4. With increasing planting density, the height and the height of center of gravityincreased, on the other hand, the stem diameter, wall thickness, culm dry mattercontent decreased, the oilseed flax presented a severe lodging phenomenon, indicatingthat in the production of oilseed flax, the increased height and height of center ofgravity by increasing planting density are the two of main causes of lodging. Underthe high plant density condition, the fluctuation of height of center of gravity, lodgingarea and cellulose content are large in variety with poor lodging resistance exhibitedbut is small in variety with strong lodging resistance, indicating the positivecorrelation between cellulose constant of culm and lodging resistance of the culm.Weak activities of biosynthesis enzymes(PAL, TAL,4CL and CAD) and low lignincontent caused by increased planting density resulting in decreased lodging resistanceof oilseed flax culm.