Effect of ontogeny, heterophylly and leaf position on the gas exchange of the hop plant

Abstract

This paper evaluates the influence of ontogeny and the position of bine and offshoot leaves on the rate of photosynthesis (P n ), transpiration (E) and stomatal conductance (g s ) in hop plants. In the ontogeny influencing P n , E and g s among hops. The highest P n was measured in phase 81-89 BBCH and E and g s in phase 61-69 BBCH. The P n increased over the course of ontogeny from the 1 st to 3 rd level of the hop plants. From the 61 BBCH phase, the leaves of the first and second level achieved a photosynthetic maturity and P n value no longer increased. The third-level leaves achieved photosynthetic maturity from the 81 BBCH phase. Higher E was measured in the upper parts of the hop plant. P n and E were higher in the bine leaves in the third level of the hop plant over the entire course of the vegetation period. In the first and second level of the hop plant, higher values of P n were measured in the offshoot leaves. Differences in g s were not noteworthy among the leaf types. Results show that a significant factor affecting the differences in P n and E in hops is the age of the leaves.

Heavy grazing effects on stem elongation and internode allometry: Insights from a natural pasture grass

“…For example, an increasing defense effect of position on leaf function has been observed from the bases to the apices of plants (Shim, Lee, Ryu, & Kang, ). Similarly, many studies have reported that photosynthesis differs dramatically from the base to the apex of plants in various species owing to differences among developmental stages (Gonzalez‐Real & Baille, ; Hejnák, Hniličková, & Hnilička, ; Mooney, Field, Gulmon, & Bazzaz, ). However, there is a dearth of information on the effects of LHG on internode characteristics among different leaf positions of ecologically and economically important grassland plants such as the dominant L. chinensis of typical Eurasian steppes.…”

Physiological response of juvenile hop plants to water deficit

“…The lowest P n occurred in genotypes Columbus and Magnum (5.10 and 5.36 μmol CO 2 /m 2 /s, respectively). Hejnák et al (2014) (Table 2). Kenny (2005) states that the average stomatal conductance was 320 mmol H 2 O/m 2 /s, and the range was between 173 and 477 mmol H 2 O/m 2 /s.…”

QTL and candidate genes for heterophylly in soybean based on two populations of recombinant inbred lines

“…Heterophylly refers to two or more types of leaves on the same plant. It may be the result of a rigid development program or a plastic response of plants to different habitat conditions ( Kerstetter and Poethiq, 1998 ; Titus et al, 2001 ; Hejnák et al, 2014 ). Few studies on heterophylly have been reported in soybean, and the genetic and molecular mechanisms remain unknown.…”

“…It is also well-known that leaf morphology is a key contributor to canopy structure and affects light distribution, ventilation permeability, and light energy utilization efficiency of a population ( Bhagsari and Brown, 1986 ; Sarlikioti et al, 2011 ). Heterophylly can allow more efficient use of light energy by affecting canopy structure, gas exchange, and light interception of the lower canopy ( Hejnák et al, 2014 ; Beyschlag and Zotz, 2017 ). For example, relatively narrow leaves on top of a plant allow more light through to the middle and lower leaves, leading to increased photosynthetic activity throughout the canopy.…”