Developmental Stages (Phenology)

Abstract

Understanding how plants sense and respond to their environment requires knowledge of the morphological and anatomical changes that take place during development and the molecular and biochemical mechanisms underlying those changes. A critical requirement for conducting such analyses is to have an accurate and precise description of every developmental stage of the entire plant and its organs (phenology) so that plant sampling for analyses is highly repeatable. Such a system would enable recognition of critical stages for optimizing yield and developing measures to assure highest possible yields. The development of the aboveground organs of many economically valuable plants has been codified in a decimal scale. The decimal scale, pioneered in cereals, was developed to increase the accuracy and precision in describing plant development; it has not previously been applied to sugarcane.The ten stages of phenology to describe the rate of sugarcane development are primarily driven by temperature. The minimum, optimum, and maximum temperatures for different stages of sugarcane development have been collated from the literature. When other factors, such as cultivar, have been shown to influence the rate of development of a process, these are discussed also. Applied to sugarcane, the decimal code has limitations: it does not include root development and there is a need to further subdivide the stages to accommodate a numbering system for leaves and internodes. The development of sugarcane root systems is discussed, even though there is relatively less known about the absolute values of temperature and soil water status that modulate root development. The molecular control of development, being unraveled in model plant systems, is only starting to be studied in the genetically more complex species such as sugarcane. Molecular control of development may prove to be more successful than transgenic targeting of primary metabolism has turned out to be for ameliorating yield-limiting processes such as partitioning of sucrose between respiration and storage.

Leaf Growth and Canopy Development of Three Sugarcane Genotypes under High Temperature Rainfed Conditions in Northeastern Mexico

“…A critical and practical requirement for conducting such analyses is to develop an accurate description of the developmental stages of the entire plant and its organs (phenology) so that plant sampling for analyses is highly repeatable. A major element needed for such an understanding is a detailed description of the changes in size, composition, and organization of the plant canopy during plant development [14]. Most field studies to date in subtropical regions in which leaf and canopy development have been described were conducted under maximum temperatures not considered to be extreme.…”

Leaf nitrogen supply improves sugarcane photosynthesis under low temperature

“…Plants were grown under greenhouse conditions for 83 d, where average air temperature was 27.2 ± 5.5°C during the day and 18.2 ± 2.5°C at night, relative air humidity (RH) was 82.5 ± 15.3%, and the maximum photo-synthetically active radiation (Q) was 830 µmol(photon) m −2 s −1 . When LNC reached 20 g kg −1 in leaves +1 [following the Kuijper numbering system (Bonnett 2014), leaf +1 is the first fully expanded leaf with visible dewlap, while leaf +3 is the third one and older than leaf +1], indicating N sufficiency for sugarcane (Santos et al 2017), plants were placed inside a growth chamber for nine days under a thermal regime of 30/20°C (day/night). During the acclimation, a group of plants received two leaf N sprays (urea at 2.5% diluted in water and Triton ® at 0.1%) in two consecutive days, defining the treatment +N.…”

Thermotolerance and Physiological Traits as Fast Tools to Heat Tolerance Selection in Experimental Sugarcane Genotypes

“…After temperature treatment, the vials were placed in an autoclave (Felisa Model FE-399) held at a pressure of 0.10 MPa and 120 • C for 10 min to completely kill plant tissue and release all of the electrolytes. As leaves of different ages might show differential response, CMT was measured on the second youngest fully expanded leaves at two phenological stages: (1) leaf development and (2) grand growth [12]. Samples collected at each phenological stage from each plot consisted of two sets (control and heat treated) of 10 leaf discs (10 mm in diameter) cut from 10 randomly selected plants within the row.…”