Control of flowering and reproduction in temperate grasses

• Published in: New Phytologist
• Main Author: HEIDE, O. M.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 1994
• Subjects: Arctic
• Online Access: http://dx.doi.org/10.1111/j.1469-8137.1994.tb04019.x; https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fj.1469-8137.1994.tb04019.x; https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1469-8137.1994.tb04019.x; https://nph.onlinelibrary.wiley.com/doi/pdf/10.1111/j.1469-8137.1994.tb04019.x

summary Temperate grasses of the subfamily Festucioideae can be grouped into two main categories according to their environmental control of flowering, species with regular long day (LD) induction, and those with dual induction requirements. The former group includes the temperate annual crosses and a few perennial species such as Phleum pratense and Poa nemoralis . These species base no winter requirement and require only LD to flower. Most temperature perennial grasses have a dual induction requirement for flowering, a primary induction which is brought about by low temperature (vernalization) and/or short days (SD), and a secondary induction which requires a transition to long days and is enhanced by moderately high temperatures. In most dual induction species SD and low temperature are interchangeable and independently able to fulfil the primary induction requirement. Yet, they are highly interactive in this process. Commonly the plants become day neutral at low temperature (0–6 °C) and primary induction takes place in both SD and LD. Primary induction is then identical with the common vernalization response. At higher temperatures induction becomes increasingly dependent on SD. until a critical temperature is reached, usually c. 12–18 °C, at which primary induction cannot take place regardless of the photoperiod. In a few species, e.g, Bromus inermts, Phalaris arundinacea and to some extent Dactylis glomeratca , the SD response predominates while low temperature induction is weak or absent. Critical temperatures and photoperiods for primary induction vary greatly among species and, within the species, among ecotypes of different geographical origin. Critical exposure time may vary from 3–4 wk in arctic‐alpine Poa species to 20 wk in some Festuca species. Generally, ecotypes from high latitudes and especially arctic‐alpine ones, have wider temperature and daylength limits and require fewer inductive cycles for primary induction than their low‐latitude counterparts. In some grasses , especially‐ arctic‐alpine ...