GR | 偏生早熟禾营养生长休眠的光温调控

偏生早熟禾营养生长休眠的

光温调控

 种植玉米、大豆等一年生作物的土地在种植季休闲期常处于无保护的裸露状态，以至于土壤中的养分大量流失，造成严重的经济和生态环境问题。近年来一些研究提出宿根地被植物（Perennial Groundcovers，PGCs）这一概念，即希望利用多年生冷季草坪用草覆盖作物空地来解决这一问题。冷季草坪草根系发达并主要于春秋季生长旺盛，能够对作物收获期后土壤起到有效的保护作用。然而，草与作物共生期存在养分竞争，草坪草品种选择不当则会影响作物的生长，因此选择、培育在作物主要生长期生长力弱的冷季草坪草是实现PGCs概念的关键。

 偏生早熟禾(Poa secunda)具有夏季营养生长休眠的特性，可作为PGCs的优良草种。为实现对偏生早熟禾夏季营养生长休眠特性更为精准高效的利用，美国爱荷华州立大学的Shui-zhang Fei团队探究了不同光温组合偏生早熟禾营养生长休眠的调控。研究通过测试不同温度与光组合对三种偏生早熟禾营养生长休眠的影响，发现32.2°C/15h (光照) 能够有效诱导营养生长休眠，而15.5°C/12h 光照则对解除休眠最为有利，21.1°C/13h到26.6°C/14h之间为维持营养生长休眠的阈值。以上结果对于进一步揭示偏生早熟禾夏季营养生长休眠的分子机制，优质PGCs筛选和培育都有着非常重要的意义。

Figure 1：Cessation of growth over 6 weeks in PI232347 (a), PI232348 (b), PI639272 (c), and red fescue, cv. Audubon (d) under temperature and day length treatment combinations of 32.2°C/15 h, 26.6°C/14 h, 21.1°C/13 h, and 15.5°C/12 h. Each data point represents the average rating recorded across 48 individuals in all replications of the experiment. Each bar represents the standard error for a particular sampling date. A greenness rating of 5 indicates thefirst stage of dormancy, and a greenness rating of 2 indicates the onset of a full summer dormancy.

Figure 2：The effect of temperature and photoperiod on three Poa secunda accessions (a) PI232347, (b) PI232348, (c) PI639272, and (d) red fescue cv.‘Audubon’. Each panel of four plants is arranged in treatment order of 32.2°C/15 h, 26.6°C/14 h, 21.1°C/13 h, and 15.5°C/12 h. Pictures were taken at the end of the 6‐week experiment.

Table 1：Differences in dormancy release responses of Poa secunda J. Presl. accessions PI232347, PI232348, and PI639272 to 26.6°C/14 h, 21.1°C/13 h, and 15.5°C/12 h treatments after being induced to dormancy in a 32.2°C/15 h growth chamber.

Figure 3：Percentage of plants in PI232347 (a), PI232348 (b), and PI639272 (c) that broke dormancy after 3 weeks in temperature and day length treatments of 26.6°C/14 h, 21.1°C/13 h, and 15.5°C/12 h. Each data point represents the average rating recorded across 30 individuals in all replications of the experiment. Each bar represents the standard error for a particular sampling date.

Figure 4：The effect of temperature and photoperiod on dormancy release of the three Poa secunda accessions (a) PI232347, (b) PI232348, and (c) PI639272 in the 15.5°C/12 h treatment, the most effective at releasing dormancy. Each panel of three pictures represents the same plant within each accession at 1, 8, and 17 days after transfer from the 32.2°C/15 h induction chamber to the 15.5°C/12 h treatment.

Figure 5：Cessation of growth in PI232347 and PI639272 when subjected to a 32.2°C/15 h (a), 32.2°C/12 h (b), 15.5°C/15 h (c), and 15.5°C/12 h (d) treatment for 31 days. Each dot represents the average of all ratings taken on that day for each accession across all replications. Each bar represents the standard error for a particular sampling date. A greenness rating of 5 indicates thefirst stage of dormancy, and a greenness rating of 2 indicates the onset of a full summer dormancy.

编译者：

雷蕾    兰州大学草地农业科技学院    教授

说明：该文仅代表编译者对论文的理解，如需参考和引用相关内容，请查阅原文。

内容来源：Grassland Research（草地研究）第1卷第1期（投稿：2022-03-25；接收：2022-03-28；刊发：2022-05-27）

DOI：https://doi.org/10.1002/glr2.12008

引用格式：Chen, A. A., Fei, S.-z., Lenssen, A. W., & Moore, K. J. (2022). Photothermal controls of vegetative dormancy in Poa secunda. Grassland Research, 1(1), 43–52. 

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