水分和温度对藜麦种子萌发出苗及籽粒产量的影响

Effects of water and temperature on seed germination and grain yield of quinoa

  • 摘要: 藜麦作为富含营养物质且喜冷凉的旱地作物, 温度和水分是限制其种子萌发和生长的必要条件, 明确温度和干旱胁迫下藜麦的出苗和生长情况对雨养旱作区藜麦高产高效种植有重要意义。本研究以河北坝上地区典型藜麦品种‘冀藜3号’为试验材料, 通过设置 ①种子萌发试验: 3个干旱胁迫处理(PEG-6000溶液渗透势分别为0、−0.3 MPa、−0.6 MPa)和4个种子萌发温度(10℃/0℃、15℃/5℃、20℃/10℃、25℃/15℃), 分析干旱和温度胁迫及其互作效应对发芽率、发芽势、根长和芽长以及超氧化物歧化酶(SOD)和过氧化氢酶(CAT)的影响, 阐明其对环境胁迫因素的响应机制。②播期试验: 在河北坝上地区设置5个播期(5月1日、5月11日、5月21日、6月1日和6月11日), 探究不同播期下环境温度和土壤水分变化对出苗率及产量的影响, 明确河北坝上冷凉地区藜麦高产的适宜种植时间。种子萌发试验结果表明: 随着温度的升高, 发芽率、发芽势、根长和芽长逐渐增加, 20℃/10℃和25℃/15℃处理下种子萌发率较高。在干旱胁迫下, 种子萌发指标整体下降。当干旱胁迫较轻(PEG-6000为−0.3 MPa)时, SOD和CAT活性较高, 种子萌发受到的影响较小。田间试验结果表明: 随着播期推迟, 藜麦出苗期间温度和籽粒产量均呈先下降后上升再下降的趋势, 以6月1日播期处理最高。相关性分析表明, 出苗率与环境温度呈正相关, 产量与株数呈显著正相关。6月1日播期出苗期间的平均气温为17.77℃, 出苗率为95.72%: 5月11日播期的出苗期间的平均温度为5.90℃, 出苗率为6.58%。相比于5月11日播期, 6月1日播期产量提高435.67 kg∙hm−2。以上结果表明, 藜麦种子能耐受一定程度的干旱胁迫, 但在低于15℃/5℃的温度下萌发表现较差。在河北坝上冷凉地区, 为确保藜麦的出苗率免受低温的负面影响, 不宜过早播种; 适宜播期在5月中旬到6月上旬, 以保证藜麦生长所需的适宜温度。此结果可为优化坝上冷凉地区藜麦种植管理提供科学依据。

     

    Abstract: Quinoa is a dryland crop that is rich in nutrients and prefers coolness. The emergence rate is one of the main factors affecting yield of crops. Temperature and water availability are necessary conditions that affect seed germination and growth of crops. Therefore, it is important to study quinoa’s emergence, field growth, and development under temperature and drought stress to achieve high-yield and high-efficiency quinoa cultivation. This study used the typical quinoa variety ‘Jili 3’ in the Bashang area of Hebei Province as the experimental material. 1) Seed germination test: three drought stress treatments (osmotic potential of PEG-6000 solution was 0, −0.3 MPa, and −0.6 MPa, respectively) and four day/night temperatures (10℃/0℃, 15℃/5℃, 20℃/10℃, and 25℃/15℃). The effects of drought and temperature stress and their interactions on the seeds germination rate and germination potential, seedling root length, shoot length, superoxide dismutase (SOD) activity, and catalase (CAT) activity were analyzed, and the response mechanism to environmental stress was clarified. 2) Sowing date test: five sowing dates of May 1, May 11, May 21, June 1, and June 11 were set up to explore the effects of different sowing dates on seed emergence rate and yield and to clarify the suitable planting time for high yield of quinoa in the cood area of Bashang, Hebei Province. The results of the seed germination test showed that the germination rate, germination potential, root length, and bud length increased gradually with the increase in temperature, and the seed germination rate was higher at 20℃/10℃ and 25℃/15℃. The seed germination index decreased under drought-stress conditions. When the drought stress was light (PEG-6000 was −0.3 MPa), the activities of SOD and CAT were higher; and seed germination was less affected. The results of the sowing date test showed that with a delay in the sowing date, the temperature and grain yield of quinoa during seed emergence first decreased, then increased, and then decreased, with the highest temperature on sowing date of June 1. Correlation analysis showed that the emergence rate was positively correlated with ambient temperature, and yield was significantly positively correlated with the number of plants. The average temperature during the emergence period of the sowing date of June 1 was 17.77℃, and the emergence rate was 95.72%. The average temperature during the emergence period of the sowing date of May 11 was 5.90℃, and the emergence rate was 6.58%. Compared with the sowing date of May 11, the yield of June 1 increased by 435.67 kg∙hm−2. The above results showed that quinoa seeds could tolerate a certain degree of drought stress, but the germination performance was poor at temperatures below 15℃/5℃. In the cold areas of Bashang, it is not advisable to sow too early to ensure that the emergence rate of quinoa is not negatively affected by low temperatures. The most suitable sowing date was from mid-May to early June to ensure a suitable temperature for the growth of quinoa. The results provide a scientific basis for optimizing the management of quinoa planting in the cold areas of Bashang.

     

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