Comparison of Morphological and Physiological Traits between Pinus brutia, Pinus halepensis, and Their Vigorous F1 Hybrids
, Yagil Osem 1 and Rakefet David-Schwartz 1,*
Round 1
Reviewer 1 Report
1. In the abstract, the purpose (aim of the work) is not clearly identified, which is necessary in my opinion. A more concise start would be something like "We investigated..." I also think that the justification for the research (its importance) should be specified more clearly and included in the abstract.
2. The work as a whole is complex and quite well organized, a fact that shows the correct and detailed documentation of the authors regarding the chosen topic.
3. There are some errors, such as: - line 106 I think is better to use needles…(plural)
- Line 162 please present better what “semi-controlled conditions” mean
4. I also recommend to make a short linguistic check.
Author Response
1. We added the following sentence to the abstract:
"In order to understand the superior hybrid phenotype, morphological traits, growth parameters, and physio-logical response to drought stress were investigated in P. brutia, P. halepensis, and their vigorous hybrids."
The justification for the research is mentioned in the last sentence of the abstract:
" Our study suggests that the hybrids exhibit a unique combination of traits that may contribute to the forest resilience in semi-arid regions undergoing climate change.
2. Thank you for the positive comment.
3. There are some errors, such as: - line 106 I think is better to use needles…(plural)
Response: we changed to all parameters to singular “Samples for plant, root, and needle dry weight (DW) were oven dried for 48 h at 65°C before weighing.”
Line 162 please present better what “semi-controlled conditions” mean
Response: We added details in parenthesis: " The plants were grown in a greenhouse under semi-controlled conditions (natural daylight and a ventilating system) from the beginning of September 2020 up to mid-October 2020. "
4. The paper had been linguistically checked.
Reviewer 2 Report
It is a very interesting research topic, which is also very likely to be meaningful for both research and practice purpose. The manuscript is quite well written and the structure is well organized. The main results are generally supportive for the conclusions. I have only some minor points for the authors：
L21: “the hybrids'” into “the hybrids”
L171-3: Do you consider clear sky only or also conduct experiments in cloudy days and how large is such effect?
Maybe you have described the methods and the meanings of the WUE and Gs in your previous studies, but here the readers would be wondering how you obtained these parameters and at which level (from leaf stomata to ecosystems) they represent the water status of the plants.
Author Response
L21: “the hybrids'” into “the hybrids”
Response: Thank you for the comment. The error was fixed.
L171-3: Do you consider clear sky only or also conduct experiments in cloudy days and how large is such effect?
Response: The experiment was conducted during September when the sky in Israel is clear for most of the time. Changes in radiation do affect stomatal conductance, however, as shown in Figure 1a, changes in radiation were minor and did not have a large effect on the physiology during the course of the experiment. Moreover, minor effects of radiation were equal across all genotypes.
Maybe you have described the methods and the meanings of the WUE and Gs in your previous studies, but here the readers would be wondering how you obtained these parameters and at which level (from leaf stomata to ecosystems) they represent the water status of the plants.
Response: We made changes in the introduction to improve the explanation of these parameters as follows:
" Among the physiological changes that occur in response to a changing environment, stomatal conductance (gsc) and transpiration rate (E) was shown to be indicators of drought response [32–35]. These parameters allow the estimation of the gas exchange between the plant and the atmosphere. Gas exchange parameters and the weight change are used to calculate the water use efficiency (WUE). This is a proxy for the amount of water used for growth. Fluctuations in stomatal conductance occur following the opening or closure of the stomata. Open stomata allow high photosynthesis and transpiration. A high transpiration rate results from a high atmospheric demand and a high water availability. The plant starts to sense drought stress when the root water influx is lower than the leaf water outflux [36,37]. "
