Daba Ketema, Warkentin Thomas D, Bueckert Rosalind, Todd Christopher D, Tar'an Bunyamin
Crop Development Centre/Department of Plant Sciences, University of Saskatchewan Saskatoon, SK, Canada.
Department of Biology, University of Saskatchewan Saskatoon, SK, Canada.
Front Plant Sci. 2016 Apr 11;7:478. doi: 10.3389/fpls.2016.00478. eCollection 2016.
Photoperiod is one of the major environmental factors determining time to flower initiation and first flower appearance in plants. In chickpea, photoperiod sensitivity, expressed as delayed to flower under short days (SD) as compared to long days (LD), may change with the growth stage of the crop. Photoperiod-sensitive and -insensitive phases were identified by experiments in which individual plants were reciprocally transferred in a time series from LD to SD and vice versa in growth chambers. Eight chickpea accessions with differing degrees of photoperiod sensitivity were grown in two separate chambers, one of which was adjusted to LD (16 h light/8 h dark) and the other adjusted to SD (10 h light/14 h dark), with temperatures of 22/16°C (12 h light/12 h dark) in both chambers. The accessions included day-neutral (ICCV 96029 and FLIP 98-142C), intermediate (ICC 15294, ICC 8621, ILC 1687, and ICC 8855), and photoperiod-sensitive (CDC Corinne and CDC Frontier) responses. Control plants were grown continuously under the respective photoperiods. Reciprocal transfers of plants between the SD and LD photoperiod treatments were made at seven time points after sowing, customized for each accession based on previous data. Photoperiod sensitivity was detected in intermediate and photoperiod-sensitive accessions. For the day-neutral accession, ICCV 96029, there was no significant difference in the number of days to flowering of the plants grown under SD and LD as well as subsequent transfers. In photoperiod-sensitive accessions, three different phenological phases were identified: a photoperiod-insensitive pre-inductive phase, a photoperiod-sensitive inductive phase, and a photoperiod-insensitive post-inductive phase. The photoperiod-sensitive phase extends after flower initiation to full flower development. Results from this research will help to develop cultivars with shorter pre-inductive photoperiod-insensitive and photoperiod-sensitive phases to fit to regions with short growing seasons.
光周期是决定植物开始开花时间和首次开花时间的主要环境因素之一。在鹰嘴豆中，光周期敏感性表现为与长日照（LD）相比，短日照（SD）下开花延迟，它可能会随着作物的生长阶段而变化。通过实验确定了光周期敏感和不敏感阶段，在这些实验中，将单株植物在生长室中按时间序列进行长日照与短日照之间的相互转移，反之亦然。八个具有不同程度光周期敏感性的鹰嘴豆种质在两个单独的生长室中种植，其中一个调节为长日照（16小时光照/8小时黑暗），另一个调节为短日照（10小时光照/14小时黑暗），两个生长室的温度均为22/16°C（12小时光照/12小时黑暗）。这些种质包括日中性（ICCV 96029和FLIP 98 - 142C）、中间型（ICC 15294、ICC 8621、ILC 1687和ICC 8855）以及光周期敏感型（CDC Corinne和CDC Frontier）反应。对照植株在各自的光周期条件下持续生长。根据之前的数据，针对每个种质在播种后的七个时间点对植株进行短日照和长日照光周期处理之间的相互转移。在中间型和光周期敏感型种质中检测到了光周期敏感性。对于日中性种质ICCV 96029，在短日照和长日照以及后续转移条件下生长的植株开花天数没有显著差异。在光周期敏感型种质中，确定了三个不同的物候阶段：光周期不敏感的诱导前期、光周期敏感的诱导期和光周期不敏感的诱导后期。光周期敏感阶段在开花开始后一直延伸到花朵完全发育。这项研究的结果将有助于培育出诱导前期光周期不敏感和光周期敏感阶段较短的品种，以适应生长季节较短的地区。
