不同水分条件下燕麦穗颈维管束结构与穗部性状的关系

为了解不同水分条件下燕麦穗颈维管束结构与穗部性状的关系，在大田栽培条件下，连续两年设置灌溉和旱作两个水分处理，以内燕5号、燕科2号、品5号、坝莜9号4个燕麦品种为材料，观测抽穗期穗颈维管束性状、灌浆速率和穗部产量性状。结果表明，燕麦穗颈维管束发育受干旱影响，干旱条件下各品种的大维管束数目、大维管束面积、大维管束韧皮部面积、大维管束导管直径较灌溉处理均显著降低,其中坝莜9号维管束各性状对干旱反应最敏感，其大维管束面积降低幅度最大，达到55.47%。灌水条件下坝莜9号两个年度大维管束面积分别较内燕5号、燕科2号、品5号高出32.66%、15.77%、9.50%；旱作条件下品5号的维管束性状优于其他3个品种，大维管束面积分别较内燕5号、燕科2号、坝莜9号高出20.04%、4.42%、 20.42%。旱作条件下4个品种的灌浆速率较灌溉处理均降低，品种间差异较大，品5号两个年度平均灌浆速率最优，分别较内燕5号、燕科2号、坝莜9号高出21.95%、21.34%、7.93%；灌水条件下坝莜9号的平均灌浆速率分别较内燕5号、燕科2号、品5号高出23.94%、28.17%、17.84%，穗粒重分别高出40.39%、 10.33%、4.27%，穗粒数分别高出40.78%、19.42%、17.37%。经相关分析，灌水条件下大维管束数目与穗长呈现极显著相关；旱作条件下大维管束导管直径与总小穗数、穗长、穗粒数呈极显著相关，其中与总小穗数相关性最大。因此，灌溉可促进燕麦维管束发育和籽粒灌浆，进而获得高产。

Relationship between the Vascular Bundle Structure of Oats Panicle Neck and Panicle Traits under Different Water Conditions

In order to study the response of oats panicle vascular bundle structure to water and its relationship with panicle traits,under the conditions of field cultivation,two water treatments of irrigation and dry farming were set up for two consecutive years,and four varieties(Neiyan 5,Yanke 2,Pin 5 and Bayou 9) were used as materials to observe the characteristics of panicle neck vascular bundles,filling rate and panicle yield characteristics at heading stage. The results showed that dry farming affected the development of oat ear-neck vascular bundles. The numbers of large vascular bundles,large vascular bundle area,large vascular bundle phloem area,and large vascular bundle diameter of each variety under dry farming conditions were significantly reduced,compared to those under irrigation condition. In the four varieties,Bayou 9 was most sensitive to dry farming in these traits. In particular,its largest vascular bundle area decreased by 55.47%. Under irrigation condition,the largest vascular bundle area of Bayou 9 was 32.66%,15.77% and 9.50% higher than that of Neiyan 5,Yanke 2 and Pin 5,respectively. Pin 5 had the best values of the vascular bundle compared to the other varieties under dry farming condition,and its largest vascular bundle area was 20.04%, 4.42% and 20.42% higher than that of Neiyan 5,Yanke 2 and Bayou 9,respectively. Dry faming decreased the grouting rate of all the four varieties,and the average grouting rate of Pin 5 was the best in two years,which was 21.95%,21.34% and 7.93% higher than that of Neiyan 5,Yanke 2 and Bayou 9,respectively. Under irrigation condition,compared to Neiyan 5,Yanke 2 and Pin 5,the average filling rate of Bayou 9 was increased by 23.94%,28.17% and 17.84%,and the grain weight per ear was increased by 40.39%,10.33% and 4.27%; the number of grains per panicle was enhanced 40.78%,19.42% and 17.37%,respectively. Correlation analysis showed that the area of large vascular bundles and phloem area were significantly positively correlated with grain number per spike and grain weight per spike. The results indicate that irrigation can promote the development of vascular bundles,increase the filling rate and yield of oats.