Genetic Variation for Cold Tolerance in Two Nested Association Mapping Populations
, Ana Butrón 1, Víctor Manuel Rodriguez 1, Renaud Rincent 2, Alain Charcosset 2, Catherine Giauffret 3, Albrecht E. Melchinger 4, Chris-Carolin Schön 5, Eva Bauer 5,†, Thomas Altmann 6, Dominique Brunel 7, Jesús Moreno-González 8, Laura Campo 8, Milena Ouzunova 9, Ángel Álvarez 10, José Ignacio Ruíz de Galarreta 11, Jacques Laborde 12 and Rosa Ana Malvar 1Round 1
Reviewer 1 Report
The paper reports a QTL study of cold tolerance in maize using two connected nested association mapping populations. Authors detected one QTL for plant weight and four for chlorophyll fluorescence under cold conditions in one of the two populations, however neither of these QTLs had great effects on the traits.
The text of the article is well and clearly written, no concerns I have regarding the methodology.
However, I have some minor suggestions for correction:
1). In Figure 1 the number of DH obtained in F353 x UH250 cross is almost invisible.
2). In the 'Results' section Table 2 looks very big, and probably should be placed on a separate sheet, or moved to supplementary materials.
3). In lines 191-192 authors report that no QTL were detected for the traits number of days from sowing to emergence, number of days from sowing to the second leaf with ligule, and early vigor. However, these traits were not mentioned neither in 'Materials and Methods' nor elsewhere in the text or tables. I suggest either to exclude these traits from results at all, or to provide some more information about them, at least how early vigor was scored.
Author Response
The paper reports a QTL study of cold tolerance in maize using two connected nested association mapping populations. Authors detected one QTL for plant weight and four for chlorophyll fluorescence under cold conditions in one of the two populations, however neither of these QTLs had great effects on the traits. The text of the article is well and clearly written, no concerns I have regarding the methodology.
R: Thanh you for your positive comments. Indeed, the number of QTL and their effects are low; which is lower than for other experimental designs; which is also very interesting for researchers willing to make these kind of studies
1). In Figure 1 the number of DH obtained in F353 x UH250 cross is almost invisible.
R: We have increased the size of those numbers
2). In the 'Results' section Table 2 looks very big, and probably should be placed on a separate sheet, or moved to supplementary materials.
R: We have moved Table 2 to supplementary materials and made the corresponding changes in the other tables
3). In lines 191-192 authors report that no QTL were detected for the traits number of days from sowing to emergence, number of days from sowing to the second leaf with ligule, and early vigor. However, these traits were not mentioned neither in 'Materials and Methods' nor elsewhere in the text or tables. I suggest either to exclude these traits from results at all, or to provide some more information about them, at least how early vigor was scored.
R: We have mentioned those traits in Materials and Methods
Reviewer 2 Report
Comments for author File: 
Comments.pdf
Author Response
- Please introduce the model of BLUE.
R: yij = µ + τi + βj + uij i = 1, 2, · · · , number of DH ; j = 1, 2, · · · , 6
yij is the random variable that represents the observation (i)-th of the block (j)-th
µ is a constant effect that measures the average level of response for all the units, called the global mean.
τi is the effect produced by the i-th level of DH line
βj is the effect produced by the j-th level of block factor.
uij is the experimental error.
- In the section of Statistical analyses, the y was the vector with N+1 adjusted phenotypic values. However, J was a N×P matrix. Why had different number of individuals on both sides of the equal sign? What was the meaning of aq and ac?
R: There was a mistake in the formula because y is a vector (N x 1). aq and ac are the column vectors (K x 1) of the intrafamily additive effects of the QTL q and cofactor c, respectively. e is a column vector (N x 1) of the residuals of the model. We have included an explanation of the formula in that section
- Please describe the construction process and information of linkage map.
R: It is explained in Giraud et al. (2014) and the two consensus maps obtained are available at Maize GDB (http://maizegdb.org/cgi-bin/displayrefrecord.cgi?id=9024747, data available on 29th December 2022).
- The number was incomplete display in Figure 1. Please remodify it.
R: we have corrected that figure
- Please check the writing format of literature cited.
R: we have verified the format of the literature
