[Background] Climate change and particularly global warming has emerged as an alarming threat to the crop productivity of field crops and exerted drastic effects on the cropping patterns. Production of cotton has been dropped down to one million bales from 1.4 million bales since 2015 in Pakistan due to the increase in temperature at critical growth stages, i.e., flowering and boll formation. Keeping in view the importance of cotton in the country, this study was conducted to investigate the genetic effects conferring heat tolerance in six populations (P1, P2, F1, F2, BC1 and BC2) developed from cross-1 and cross-2, i.e., VH-282 × FH-142 and DNH-40 × VH-259.
[Results] The results revealed that cross-1 performed better in heat stress as compared with cross-2 for majority of the traits recorded. Boll weight and ginning outturn (GOT) were highly effected under heat stress and had negative correlation with Relative cell injury (RCI). Boll weight, fiber length, fiber strength and fiber fineness were under the control of non-additive gene action, whereas RCI was controlled by additive gene effects. Lower values of genetic advance coupled with higher values of broad sense heritability for these traits except RCI confirmed the role of non-additive genetic effects. Duplicate types of epistasis were recorded for fiber strength in cross-1 in normal condition. However, complementary type of non-allelic interaction was recorded for fiber strength under normal condition, fiber fineness and RCI under heat stressed condition in cross-1. Likewise, boll weight, GOT and fiber length in populations derived from cross-2 in normal condition were also under the influence of complementary type of non-allelic interaction. Significant differences among values of mid parent and better parent heterosis for boll weight in both normal and heat stress condition provided the opportunity to cotton breeders for utilization of this germplasm for improvement of this trait through exploitation of heterosis breeding.
[Conclusion] Cross-1 performed better in heat stress and could be utilized for development of heat tolerant cultivar. RCI was under the influence of additive gene action, so one can rely on this trait for screening of large number of accessions of cotton for heat stress. While other traits were predominantly controlled by non-additive gene action and selection based on these should be delayed in later generations.
[Authors] SALMAN Muhammad, ZIA Zia Ullah, RANA Iqrar Ahmad, MAQSOOD Rana Haroon, AHMAD Saghir, BAKHSH Ali, AZHAR Muhammad Tehseen
Journal of Cotton Research. 2019; 2: 9
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CIRAD – France
In Cameroon, water shortage is the major abiotic factor limiting cotton (Gossypiumhirsutum L) yield and lint quality. Understanding cotton physiological responses to water supply and their consequences on growth and development therefore provides insight into the problem of yield stagnation. The underlying strategies for yield maintenance under water deficit in Cameroon have not been well understood. The objective of this paper is to evaluate which ecophysiological traits could confer a good response to drought among a panel of cotton genotypes used in Cameroon. These genotypes were compared in field and greenhouse trials under potential and water-limited conditions (fraction of soil transpirable water range: 0.39 to 0.83). Water deﬁcit had a negative impact on almost all the plant functions, both under field and controlled environments. The recent cultivar L484 bred for the driest production area responded quite differently from the other cultivars in this study. L484 had the fastest development, thickest leaves with the most chlorophyll and thus maintained the highest level of photosynthesis and transpiration per unit of leaf area in water-limited conditions. In these conditions, L484 had the highest radiation use eﬃciency and water use efficiency maintenances. However, despite the advances in cotton breeding in Cameroon, no significant improvement between old cultivars and recently released ones were found on biomass, harvest index and cotton yield across water conditions. The lint percentage was the only yield component significantly enhanced, irrespective of water status.
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CIRAD – France
Seed cotton (Gossypium hirsutum L) yield in Northern Cameroon has been declining since the 80s despite breeding eﬀorts. We used a set of widely grown cotton cultivars released at different dates to study genetic improvement under different cropping conditions in Cameroon, and in controlled conditions. The genetic gain was estimated with a linear regression of the variety mean on its year of release (YR). Contrasts between genetic gains observed with different planting dates were estimated and tested. Our results revealed a genetic improvement on ﬁber yield of 3.3 kg ha-1 year-1 due to increased ginning out-turn. However, there was no genetic improvement on aerial biomass, harvest index or seed cotton yield. At the early stage of development, aerial and root biomass, and potential root extraction ratio of nutrients decreased with YR. So did leaf number and hairiness at the beginning of flowering. Carbon dioxide assimilation was not affected by YR. Neither were crop cycle duration and phyllochron. Although the potential of almost all fiber technological characteristics was improved under favorable water conditions, some (upper half mean length, short fiber index, uniformity index, and strength) were reduced in water-limited conditions. We concluded that cotton breeding efforts in Cameroon have successfully improved cotton fiber yield and the potential of most fiber technological characteristics. However, in water-limited conditions, fiber quality tended to decrease with the YR. There is still some room for seed cotton yield improvement.
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Professor Hezhong DONG, Cotton Research Centre, Shandong Academy of Agricultural Sciences, China;
Professor Zhiguo ZHOU, Nanjing Agricultural University, China
Journal of Cotton Research is hosting a thematic series on cotton physiology and pathology. The research community is encouraged to share original findings, methodology, results, databases, and/or software and opinions.
Scopes that may be covered in the submissions may include, but are not limited to the following:
1. growth and organ development;
2. plant and shoot architecture;
3. water, fertilizer, light, etc. use efficiency;
4. intelligent agriculture;
5. rhizosphere and other plant-environment interactions;
6. main disease and resistance.
Submission Deadline: 30 September 2019
The Seventh Meeting of the Asian Cotton Research and Development Network was held at Nagpur during 15-17 September 2017. The Indian Society for Cotton Improvement (ISCI), Mumbai hosted the meeting together with the ICAR-CICR (Central Institute for Cotton Research), Nagpur and ICAR-CIRCOT (Central Institute for Research on Cotton Technologies). The main theme of the meeting was PRODUCING QUALITY FIBRE & DOUBLING COTTON FARMERS INCOME. Cotton researchers from public and the private sector participated. Dr. C. D. Mayee, President, Indian Society for Cotton Improvement, was the chairman, of the organizing Committee. The meeting elected Dr. Prashant G. Patil as Chairman of the Network until the next meeting. Eminent cotton experts i.e., Dr. Timorthy Dennehy, Dr Judith Brown, Dr Albert Santos from US; Dr Derek Russell from Australia, Dr Negm from Egypt and several senior research leaders from India and Bangladesh attended the meeting. The proceedings, recommendations, presentations and abstracts of the meeting can be accessed here.
Proceedings are available
The Seventh Meeting of the Asian Cotton Research and Development Network was held at Nagpur, India during 15-17 September 2017. The Indian Society for Cotton Improvement (ISCI), Mumbai hosted the meeting together with the ICAR-CICR (Central Institute for Cotton Research), Nagpur and ICAR-CIRCOT (Central Institute for Research on Cotton Technologies).
The main theme of the meeting was “PRODUCING QUALITY FIBRE & DOUBLING COTTON FARMERS INCOME.” Cotton researchers from public and the private sector participated. Dr. C.D. Mayee, President, Indian Society for Cotton Improvement, was the Chairman of the Organizing Committee. The meeting elected Dr. Prashant G. Patil as Chairman of the Network until the next meeting. Eminent cotton experts like Dr. Timorthy Dennehy, Dr Judith Brown, Dr Albert Santos from US; Dr Derek Russell from Australia; Dr Negm from Egypt and several senior research leaders from India and Bangladesh attended the meeting.
The proceedings, recommendations, presentations and abstracts of the meeting are now available at the ICAC website.
With the recent completion of draft sequencing of diploid cotton Gossypium raimondii and G. arboreum genomes published in Nature Genetics, and the first “gold-standard” version of G. raimondii genome published in Nature, cotton research community enjoyed the pick of many seminal research results that have provided a glorious opportunity to study orthologous and paralogous genes and gene families in allotetraploid cotton.
These successes and great achievements in ancestral diploid genome sequencing further resulted in decoding of the representative genome of widely grown allotetraploid Upland (G. hirsutum L.) cotton, Texas Marker-1.
Two independent research papers published in Nature Biotechnology by Zhang et al. and Li et al. in this week issue described the complex allotetraploid TM-1 genome that further entered cotton research to an era of “golden” opportunities providing the first insights into allotetraploid cotton genome structure, genome rearrangements, gene evolution, cotton fiber biology and biotechnology that will help to rapidly translate the genomics “knowledge” to an “economic impact”!
Congratulation to all cotton community with these latest achievements, high impact journal seminal publications, and hard work to foster cotton research!