尿素对阔世玛胁迫下紫苏的影响

The Effect of Urea on Perilla frutescens( L. )Britt. under Sigma Broad Stress

为探讨尿素对阔世玛胁迫下紫苏幼苗的缓解效应,阐明适宜紫苏生长的最佳除草施肥条件。以六叶期紫苏幼苗为材料,研究了5个尿素浓度（0、1、2、4和8g/L）和5个阔世玛浓度（0、0.125、0.25、0.5和1.0mL/L）对紫苏光合特性指标、子粒产量和紫苏田杂草防效的影响。结果表明,阔世玛显著降低了紫苏叶片的叶绿素含量指数、净光合速率和气孔导度,胞间CO2浓度升高,说明阔世玛显著抑制紫苏的光合性能,且表现出一定的剂量-效应关系;而1-4g/L的尿素处理则效果相反。1-4g/L的尿素和不同浓度的阔世玛先后处理,比单用阔世玛处理效果好,先施4g/L的尿素,后施0.5mL/L阔世玛,能显著缓解阔世玛对紫苏的胁迫,提高其光合性能和产量。该施药模式具有平衡除草施肥技术和安全高产的特点,有较高的推广价值。

Perilla with six leaves was exposed to combination treatment with urea（0,1,2,4 and 8g /L） and sigma broad（0,0. 125,0. 25,0. 5 and 1. 0mL /L） of different concentration to study the mitigative effect of urea on Perilla frutescens（L.） Britt. Seedlings under sigma broad stress and confirm the best treatment style. The effect of combination treatment on photosynthesis,weed control and seed yield of Perilla frutescens（L.） Britt. was studied by using the randomized block experiment design. The results showed that the chlorophyll content index,photosynthetic rate（Pn） and stomatal conductance（Gs） are reduced significantly,while the intercellular CO2concentration（Ci） was increased under the sigma broad treatments. It indicated that sigma broad significantly inhibited the photosynthetic capacity. It also showed that sigma broad treatment with urea at moderate concentration（1 to 4g /L） could antagonize the negative effect contributed by sigma broad,while high concentration（8g /L） aggravated this effect. These results indicated that the mitigative effect of urea on Perilla frutescens（L.） Britt. Seedlings to Puma super stress is increased effectively. The photosynthesis was improved when treated by 4g /L urea first and then by 0. 5mL /L sigma broad. This combination of urea and sigma broad could balance the fertilization and weeding,security and high yield,promote crop production,and exhibit great potentials for practical application.