1 research outputs found
Developmental patterns of a large set of barley (Hordeum vulgare) cultivars in response to ambient temperature
Ambient temperature plays an important role in plant development. In cereals,
little is known about the exact effects of ambient temperature in the range
between it being a vernalising agent and an abiotic stress factor; thus the genetic
determinants involved in the registering and response to ambient temperature,
and their natural variation has not been dissected either. Principally, we
wished to establish the level of natural variation in response to ambient
temperature in barley via studying plant phenological development. The
responses to temperature of 168 barley genotypes of different provenances
and seasonal growth habit groups were observed in controlled environments.
The effects of four temperature regimes (13â—¦C, 16.5â—¦C, 18â—¦C and 23â—¦C) on the
duration of plant phenophases were examined. The plant development was
characterised in a series of consecutive phenophases that span the plant life
cycle from germination through flowering to attainment of maximum plant
height. Ambient temperature affected significantly plant development, with
substantial variation in responses among the genotypes. Six major types of
responses were identified, which depended strongly on seasonal growth habit,
with only a small degree of overlap. Although the differences in the timing of
development among clusters were significant under each temperature regime,
the 23â—¦C treatment resulted in the largest diversity of responses, with significant
changes in the ranking of the six clusters compared to other treatments. Two
clusters showed particularly unusual responses to 23C: the development of
one winter barley cluster was extremely accelerated by the 23C treatment,
whereas the development of one spring barley cluster was significantly delayed.
Ambient temperature assumes importance as a regulatory cue in the intricate
and complex temporal and spatial regulation network of plant development in
cereals and acts mostly through its regulatory effect on certain developmental
phases such as the onset and duration of the intensive stem elongation