The study 'Nucleo-cytoplasmic interactions affecting biological performance of Lipaphis erysimi (Kaltenbach) in Brassica juncea' looks very impressive at first instance. But there are serious flaws in the study as follows:

1. Why the susceptible check was not included in the study?
2. In the methodology, authors have labelled five plants as five replications. Making individual plants as one replication in a randomized block design will lead to high inter-replication variation. Why not a set of five/ten plants was considered as one replication when you have sufficient number of plants in each row (Same size should be representative).
3. Authors have not made it clear, how the aphids were released. As per Dhillon et al. (2018) authors infested the test plants artificially with pieces of infested Brassica twigs pinned to the plant. Pinning of host plants inflicts mechanical injury which activates the myrosinase-glucosinolate defense system in Brassica plants which in turn interferes with expression of natural resistance.
4. Authors have covered the branches with twig cages. Covering the branches with twig cages alters the microclimate leading to physiological and nutritional deviation from naturally grown plants. It has been observed that cages plants exhibit normal growth with twisted twigs etc. which interferes with their natural expression of resistance. How did authors address this problem?
5. As explained in Dhillon et al. (2018) authors have worked out both aphid population index (API) and aphid damage index (ADI) each on 0-5 scale. Aphid resistance index (ARI) is then worked out by taking mean of the two. While ADI is based on the degree of damage done to host plant, API is based on aphid population - higher the pest numbers more the API will be. Some plants may harbor higher aphid population without exhibiting significant damage and vice versa because of differences in their inherent resistance/susceptibility. Thus, inclusion of API in calculations of Aphid Resistance Index the true resistance exhibited by host plant. Earlier workers, Bakhetia and Sandhu (1973) did not use population data in calculations of Aphid Infestation Index (AII) as AII is based on the degree of injury inflicted on the host plant.
6. For the calculation of multiplication rate, I suggest the authors to give a relook to population demography parameters in various text books such as https://doi.org/10.1017/CBO9780511975387 and recalculate the multiplication rate accordingly.
7. In Dhillon et al. (2018) authors have argued that bioassays with excised leaves have been associated with induced resistance and is not representative of plant origin. Then why this method is used here?
8. In biochemical analysis part, authors have analyzed only glucosinolates and myrosinase and ignored many other defense metabolites (phenols, flavonols and enzymes) which are known to play significant role in plant defense. Why were these not analyzed. Thus, it appears to be an incomplete study. Further, it is a well known fact that Lipaphis erysimi is a sap feeder. Aphid stylet movement in plant tissue is intercellular with little damage (that too during probing or feeding) or no damage when there is no probing, which is hardly perceived by host plant. And for myrosinase-glucosinolate defense system to be active in plant defense, tissue damage is critical in bringing myrosinase in close contact with glucosinolates which mostly occurs in chewing insects (Hopkins et al. 2009).
9. In the results section, need to have a relook at the data and rewrite the results accordingly. Individual comments on the body of the text (File attached).
10. Discussion part of poorly written and needs to be rewritten.
11. In table 2, I suggest authors to try splitting the toal development period data to nymphal period and adult longevity. For details see individual comment on table 2.
12. Table 3. Since nymphal survival is recorded upto 48 hrs only, it should be reflected in the table.
13. And above all, in the discussion authors have made the statement that use of these male sterile cytoplasms in development of B. juncea hybrids could be useful for reducing losses caused by L. erysimi. If you see the Aphid Resistance Index data in table 1, all lines have ARI values ranging from 3.0 to 5.0 which fall under susceptible to highly susceptible category (Dhillon et al. 2018). If all the lines are susceptible to highly, susceptible then they have no potential to be used further in hybrid breeding. Thus, the claims made in this paper get forfeited. In light of that, I don't think this paper is worth publishing as there is no significant finding (all lines are susceptible). Check List a. Is the quality of the figures and tables satisfactory? No b. Does the reference list cover the relevant literature adequately and in an unbiased manner? No c. Are the statistical methods valid and correctly applied? (e.g. sample size, choice of test) No d. Is a statistician required to evaluate this study? No e. Are the methods sufficiently documented to allow replication studies? Yes QUALITY ASSESSMENT: Rigor 2 Quality of the writing 2 Overall quality of the content 2

Despite the self contradictory data in the paper, I wonder how this article managed to appear. The data says all lines are susceptible to highly susceptible but the paper says they are promising. Single plant is used as a replication.