Influence of Parental Dura and Pisifera Genetic Origins on Oil Palm Fruit Set Ratio and Yield Components in Their D × P Progenies

Round 1

Reviewer 1 Report

Round 1:

The primary objective of oil palm growers and breeding programs is to increase oil yield. Emphasis on genetic planting materials is the first stage in high yield achievement in order to achieve maximum output per unit area. Oil palm fruit set and oil yield are known to be influenced by different genetic materials that had been used as parents to develop, for example, dura × pisifera progenies. Unsuitable D×P progeny planting materials may result in a low fruit set coupled with a loss in oil yield. In this study, the authors investigated parental dura and pisifera genetic origins on fruit set and yield components in D×P progenies Herein authors evaluated 24 progenies, indicating that the progeny PK4674 could be used in future biparental hybridization as an elite novel breeding material for fruit set and oil yield improvement. The article seems important due to the growing demand for vegetable oil, which is associated with the need to increase the production of the oil palm yield, which results from the constantly growing demand of the population.

The experiments and evaluation of the plant materials appear to be well planned. The statistical methods used herein are appropriate. English style ad grammar is fine.

Below are some comments/questions and minor corrections:

1. Where did these materials come from frim, a seed bank from private farmers?
2. Can you give the number of the generation of these progenies used?
3. It is good to enter the total number of measurements. It says that the data was collected 3 times a year for 5 years. Add a sum sentence.
4. Please provide a source for NIFOR.
5. Can you put photographic documentation of the plant materials?

L42  demand. [1] - unnecessary dot

L54 important. [4]- unnecessary dot

L63 MPOB – please provide a description of this shortcut

L135 NIFOR – please provide a description of this shortcut

Round 2:

The authors answered my questions comprehensively. The corrections made in the manuscript are fully sufficient

Reviewer 2 Report

Round 1:

The manuscript entitled "Influence of parental dura and pisifera genetic origins
on fruit set ratio and yield components in their D×P progenies" is a nice attempt to make research progress in the oil tree crops. But I didn't find any novelty or new technological usage in their research. Even the title doesn't include the crop species name. The manuscript consists of a lot of big tables that are unnecessary. Different equations are represented in the statistical analysis that are very basic and not need to write in the manuscript because those are very well known and hardly authors can mention the citation for those. So I am rejecting the manuscript from its publication.  

Round 2: Now the article can be published.

This manuscript is a resubmission of an earlier submission. The following is a list of the peer review reports and author responses from that submission.

Round 1

Reviewer 1 Report

The primary objective of oil palm growers and breeding programs is to increase oil yield. Emphasis on genetic planting materials is the first stage in high yield achievement in order to achieve maximum output per unit area. Oil palm fruit set and oil yield are known to be influenced by different genetic materials that had been used as parents to develop, for example, dura × pisifera progenies. Unsuitable D×P progeny planting materials may result in a low fruit set coupled with a loss in oil yield. In this study, the authors investigated parental dura and pisifera genetic origins on fruit set and yield components in D×P progenies Herein authors evaluated 24 progenies, indicating that the progeny PK4674 could be used in future biparental hybridization as an elite novel breeding material for fruit set and oil yield improvement. The article seems important due to the growing demand for vegetable oil, which is associated with the need to increase the production of the oil palm yield, which results from the constantly growing demand of the population.

The experiments and evaluation of the plant materials appear to be well planned. The statistical methods used herein are appropriate. English style ad grammar is fine.

Below are some comments/questions and minor corrections:

1. Where did these materials come from frim, a seed bank from private farmers?
2. Can you give the number of the generation of these progenies used?
3. It is good to enter the total number of measurements. It says that the data was collected 3 times a year for 5 years. Add a sum sentence.
4. Please provide a source for NIFOR.
5. Can you put photographic documentation of the plant materials?

L42  demand. [1] - unnecessary dot

L54 important. [4]- unnecessary dot

L63 MPOB – please provide a description of this shortcut

L135 NIFOR – please provide a description of this shortcut

Reviewer 2 Report

The manuscript entitled "Influence of parental dura and pisifera genetic origins
on fruit set ratio and yield components in their D×P progenies" is a nice attempt to make research progress in the oil tree crops. But I didn't find any novelty or new technological usage in their research. Even the title doesn't include the crop species name. The manuscript consists of a lot of big tables that are unnecessary. Different equations are represented in the statistical analysis that are very basic and not need to write in the manuscript because those are very well known and hardly authors can mention the citation for those. So I am rejecting the manuscript from its publication.  

Reviewer 3 Report

See attached pdf file for comments

Comments for author File: Comments.pdf

The Authors response:

The Editor-in-Chief,
Agronomy Journal.

Dear Chief-Editor,

COVER LETTER WITH RESPONSES TO REVIEWERS’ COMMENTS We hereby write to inform your noble office that based on the reviewers' comments and editorial evaluation, the manuscript ID (Agronomy-959534) of this paper “Influence of parental dura and pisifera genetic origins on oil palm fruit set ratio and yield components in their D×P progenies”, has been addressed in the main manuscript and changes made are highlighted.

First Reviewer:

Q:1.Where did these materials come from, a seed bank from private farmers?

A: The parents of the 24 progenies were brought to Malaysia through germplasm collection from different countries such as Nigeria, Angola, Cameroon, etc. Whereas, the progenies were developed through closed pollination using hybridization breeding technique.

Q:2. Can you give the number of the generation of these progenies used?

 The progenies used in this study are F1 hybrid - single generation.

Q:3. It is good to enter the total number of measurements. It says that the data was collected 3 times a year for 5 years. Add a sum sentence.

A: 1. Yield and yield components: Two weeks intervals or 2 rounds per month (120 rounds for 5 years).
    2. Fruit bunch quality components: Four months interval (15 rounds for 5 years).
    3. Vegetative measurement: A single-round vegetative and physiological trait measurement was done.

Q:4. Can you put photographic documentation of the plant materials?

A:  The photographic illustration of the oil palm progenies is presented in Figure 1 in the manuscript.

Q:5. L42 demand. [1] - unnecessary dot; L54 important. [4]- unnecessary dot

A: It was a full stop (.) but the correct reference format has been done; It was a full stop (.) and the author has been inserted after the full stop.

Q:6. L63 MPOB – please provide a description of this shortcut; L135 NIFOR – please provide a description of this shortcut

A: MPOB means Malaysian Palm Oil Board as indicated in L9.; NIFOR means Nigeria Institution for Oil Palm Research.

Second Reviewer:

Q:1.The title doesn't include the crop species name

A: The crop species name: Oil palm which is a common name for Elaeis guineensis has been added to the topic.

Q:2.The manuscript consists of a lot of big tables that are unnecessary.

A: The traits analysed and presented in the tables could have direct or indirect effects on oil palm fruit set and oil yield.

Q:3.Different equations are represented in the statistical analysis that are very basic and not need to write in the manuscript

A: The different equations represented in the statistical analysis has been expunged completely from the manuscript.

Third Reviewer:

1.what are the economic ramifications between what is called low oil and high oil in these combinations

 In remote rural areas, where alternative employment is scarce, the majority of oil palm jobs are located, thereby helping to foster rural growth and alleviate poverty (Russell, 2018). Therefore, low oil yield will cause a decline in the economic contribution of the industry. For the Malaysian oil palm industry, the most challenging year was 2018 with the lower oil palm production (19.52 t/ha), including its prices and exports (Kushairi et al., 2019).
High oil yielding palm varieties have potential economic benefits in its growing nations especially the small-scale farmers. High oil yield will increase the gross domestic product (GDP) of a country that is engaged in oil palm production thereby contributing to the national economy and alleviate rural poverty. The export capacity of the country increases thereby reduces trade deficit among nations. Asian Gari (2018) reported that millions of people from Malaysia and Indonesia have been lifted out of poverty through the palm oil industry, which jointly accounts for about 85% of global production. Through high oil yield, 4.5 million people are employed by the Indonesian palm oil industry and account for 1.6% of gross domestic product (GDP) (Asian Gari, 2018). Oil palm is the biggest single contributor in the economy of Indonesia with a yearly foreign exchange of more than $18 billion since a huge quantity of the harvest is exported (Asian Gari, 2018).

2.How does this paper differ from previous studies on the subject?

 This paper differs from previous studies because the breeding materials (progenies), location, palm age and soil type (deep peat soil) have not been carried out in details as in this current study.

3.Are these combinations broader in terms of genetic diversity than previous studies?

 Since this current study is about oil palm fruit set and oil yield, the oil yield of the progenies was higher than the findings of Rafii et al. (2012), but lower than the findings of Rajanaidu and Ainul (2013). In the previous studies and this current study, different progenies emerged as the highest for oil yield which could be as a result of their genetic makeup. The presence of genetic variation was noticed. We recommend that future studies incorporate molecular studies with conventional breeding.

4.What studies have been done previously to determine the relative impacts of GXE?

 Stability analysis of oil yield in oil palm (Elaeis guineensis) progenies in different environments by Rafii et al. ((2012), on four different locations (Kluang in Johor, Kepong in Selangor and Carey Island in Selangor, and Teluk Intan in Perak) with 38 DP progenies.

5.GXE a major contributor to Variability in regard to these traits?

 Genotype × environment (G×E) could be a major contributor for a better result, but could not be appropriate in this present study, since the 24 progenies of oil palm were only planted at one location (Teluk Intan in Perak) and due to the long breeding cycle of oil palm.

6.How representative is this environment of the TPE of the crop?

 According to de Almeida Rios et al. (2018), the mean yearbook temperature was approximately 27 OC, with 32 OC maximum, 21 OC minimum, and relative humidity of about 85%. The total mean yearly rainfall was approximately 2100 mm.

7.I’m assuming this is a non-seasonal crop with ongoing harvesting.

 Yes, oil palm is a perennial crop structurally different from annual crops in several ways. In annual crops, growers can take advantage of new seeds with each growing season.

8.If so, is there a correlation between seasonal harvests and yield?

 There could be a correlation between seasonal harvests and the yield of oil palm. According to Chow et al. (1992), significant positive yield and rainfall correlations at lags of 20-24 and 10-11 months (before harvest) specifically relate to the critical periods of sex differentiation and inflorescence abortion, respectively, whose results tend to be very different from those of Peninsular and East Malaysia.
However, during data collection, no data was collected on rainfall, temperature, humidity, etc.

9.Is variance the same?

 There could be differences in the variance of oil palm seasonal harvests and yield. There are 53 % to 57% variations in oil palm yield due to season, independent of the long-term trend, 12% to 24% due to rainfall, and l0% to 20% due to tagged yield effects (Chow et al. (1992).

10.There is no mention of irrigation.

 Special irrigation was not required in 11 years old oil palm plantation with a total experimental area of 12.06 hectare. however, an efficient and appropriate drainage system serving as a major factor for oil palm cultivation on peat soil was constantly managed, as seen in the figure 1.

11.Are there distinct dry and wet periods that might impact yield?

 Yes, dry and wet periods might impact yield greatly. In Malaysia, rainfall levels are among the highest, with high humidity of about 90% and the peak rainy season is from November to January, and in January, precipitation will reach 368 mm (14.5 inches) (Rodgers 2019). Within the monsoon season, there is considerable variability, including variations between periods of heavy rainfall (wet spells) and low rainfall (dry spells), and Such variations can lead to extreme wet and dry regional conditions that harm agricultural yields (Tsiang et al., 2014).

12.How is this controlled?

 Is difficult to control the weather, but in terms of dry season drainage can be applied to alternate for insufficient rainfall which is currently been used in the area where this current study was carried out. However, in terms of distinct raining season man has no control over the weather especially in field experiments like this.

13.Limitations

 Modern plant breeding is based on the fundamental principles of inheritance; however, conventional breeding methodologies have been widely successful in the production of germplasm and plant cultivars (Jiang, 2013). Funding and location were some of the limitations for not combining conventional and molecular research in the present study.
Also, the distance from the research field to Bagan Datuk Metrological Station was approximately more than 10 km away, which served as a limitation for data collection on environmental factors such as rainfall, temperature, humidity, sunshine duration, evaporation rate.

14.Conclusion

 The entire conclusion was improved.

 We hope you find our research manuscript appropriate for publication, we just appreciate your consideration and assistance to handle this manuscript.
Yours sincerely, Prof. Dr. Mohd Y. Rafii, Institute of Tropical Agriculture and Food Security, Universiti Putra Malaysia (UPM) 43400 Serdang, Selangor, Malaysia.
Email address: [email protected]