scholarly journals Dioecious hemp (Cannabis sativa L.) plants do not express significant sexually dimorphic morphology in the seedling stage

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Lesley G. Campbell ◽  
Kristen Peach ◽  
Sydney B. Wizenberg

AbstractSome economically important crop species are dioecious, producing pollen and ovules on distinct, unisexual, individuals. On-the-spot diagnosis of sex is important to breeders and farmers for crop improvement and maximizing yield, yet diagnostic tools at the seedling stage are understudied and lack a scientific basis. Understanding sexual dimorphism in juvenile plants may provide key ecological, evolutionary and economic insights into dioecious plant species in addition to improving the process of crop cultivation. To address this gap in the literature, we asked: can we reliably differentiate males, females, and co-sexual individuals based on seedling morphology in Cannabis sativa, and do the traits used to distinguish sex at this stage vary between genotypes? To answer these questions, we collected data on phenotypic traits of 112 C. sativa plants (50 female, 52 male, 10 co-sexuals) from two hemp cultivars (CFX-1, CFX-2) during the second week of vegetative growth and used ANOVAs to compare morphology among sexes. We found males grew significantly longer hypocotyls than females by week 2, but this difference depended on the cultivar investigated. Preliminary evidence suggests that co-sexual plants may be distinguished from male and female plants using short hypocotyl length and seedling height, although this relationship requires more study since sample sizes of co-sexual plants were small. In one of the cultivars, two-week old male plants tend to produce longer hypocotyls than other plants, which may help to identify these plants prior to anthesis. We call for increased research effort on co-sexual plants, given their heavy economic cost in industrial contexts and rare mention in the literature. Our preliminary data suggests that short hypocotyl length may be an indicator of co-sexuality. These results are the first steps towards developing diagnostic tools for predicting sex using vegetative morphology in dioecious species and understanding how sexual dimorphism influences phenotype preceding sexual maturity.

Inventions ◽  
2021 ◽  
Vol 6 (3) ◽  
pp. 52
Author(s):  
Rajan Kapoor ◽  
Aniruddha Datta ◽  
Michael Thomson

Conventional breeding approaches that focus on yield under highly favorable nutrient conditions have resulted in reduced genetic and trait diversity in crops. Under the growing threat from climate change, the mining of novel genes in more resilient varieties can help dramatically improve trait improvement efforts. In this work, we propose the use of the joint graphical lasso for discovering genes responsible for desired phenotypic traits. We prove its efficiency by using gene expression data for wild type and delayed flowering mutants for the model plant. Arabidopsis thaliana shows that it recovers the mutation causing genes LNK1 and LNK2. Some novel interactions of these genes were also predicted. Observing the network level changes between two phenotypes can also help develop meaningful biological hypotheses regarding the novel functions of these genes. Now that this data analysis strategy has been validated in a model plant, it can be extended to crop plants to help identify the key genes for beneficial traits for crop improvement.


2021 ◽  
Vol 2 (1) ◽  
Author(s):  
Massimo Vischi ◽  
Nicola Zorzin ◽  
Maria Bernhart ◽  
Johanna Winkler ◽  
Dipak Santra ◽  
...  

Abstract Background Global warming and issues in favour of a more sustainable agriculture suggest a reconsideration of minor cereals in European agrosystems. Compared to other summer crops, proso millet has a remarkable drought resistance and could be used to improve crop rotation and biodiversity. Proso millet is also increasingly sought by industry to produce novel foods such as those designed for coeliac patients. In this study, a thorough characterization of 11, commercially available, proso millet (Panicum miliaceum L.) varieties was carried out as a preliminary step for crop reintroduction and breeding in Western Europe. Methods The cultivars under evaluation were introduced from Austria, Poland, Russia, and the USA (University of Nebraska–Lincoln). Plants were grown at Udine (NE Italy) and Gleisdorf (Styria, Austria), under greenhouse and field conditions, respectively. Yield components and a range of morphophysiological characters were recorded in both locations. In parallel, 85 SSR markers were tested on DNA samples extracted from randomly chosen plants of each variety and the 12 responsive markers used to genotype the whole variety set. Results Morphometric analyses showed that varieties have several diverging phenotypic traits and architectures. In all instances, yields recorded at field level were much lower than potential yields. In this respect, US selections were comparable to earlier developed European varieties, suggesting that breeding for an increased adaptation is the keystone for a stable reintroduction of millet in Western Europe. Molecular analyses uncovered remarkably low genetic differences and heterozygosity levels within cultivars, confirming millet as an essentially autogamous species; in contrast, large genetic distances were noted among cultivars selected in different environments. Results of SSR genotyping combined with those originating from phenotypic analyses indicated possible crosses to source the genetic variability necessary for selection. Conclusions This study enabled the identification of cultivars that could be used to revitalize the crop in Western Europe and to produce genetically variable hybrid progenies exploitable by breeding.


2021 ◽  
Vol 12 ◽  
Author(s):  
Tien Dung Nguyen ◽  
Van Hien La ◽  
Van Duy Nguyen ◽  
Tri Thuc Bui ◽  
Thi Tinh Nguyen ◽  
...  

Soybean is a globally important crop species, which is subject to pressure by insects and weeds causing severe substantially reduce yield and quality. Despite the success of transgenic soybean in terms of Bacillus thuringiensis (Bt) and herbicide tolerance, unforeseen mitigated performances have still been inspected due to climate changes that favor the emergence of insect resistance. Therefore, there is a need to develop a biotech soybean with elaborated gene stacking to improve insect and herbicide tolerance in the field. In this study, new gene stacking soybean events, such as bialaphos resistance (bar) and pesticidal crystal protein (cry)1Ac mutant 2 (M#2), are being developed in Vietnamese soybean under field condition. Five transgenic plants were extensively studied in the herbicide effects, gene expression patterns, and insect mortality across generations. The increase in the expression of the bar gene by 100% in the leaves of putative transgenic plants was a determinant of herbicide tolerance. In an insect bioassay, the cry1Ac-M#2 protein tested yielded higher than expected larval mortality (86%), reflecting larval weight gain and weight of leaf consumed were less in the T1 generation. Similarly, in the field tests, the expression of cry1Ac-M#2 in the transgenic soybean lines was relatively stable from T0 to T3 generations that corresponded to a large reduction in the rate of leaves and pods damage caused by Lamprosema indicata and Helicoverpa armigera. The transgenic lines converged two genes, producing a soybean phenotype that was resistant to herbicide and lepidopteran insects. Furthermore, the expression of cry1Ac-M#2 was dominant in the T1 generation leading to the exhibit of better phenotypic traits. These results underscored the great potential of combining bar and cry1Ac mutation genes in transgenic soybean as pursuant of ensuring resistance to herbicide and lepidopteran insects.


2021 ◽  
Vol 12 ◽  
Author(s):  
Laura Siles ◽  
Kirsty L. Hassall ◽  
Cristina Sanchis Gritsch ◽  
Peter J. Eastmond ◽  
Smita Kurup

Seed yield is a complex trait for many crop species including oilseed rape (OSR) (Brassica napus), the second most important oilseed crop worldwide. Studies have focused on the contribution of distinct factors in seed yield such as environmental cues, agronomical practices, growth conditions, or specific phenotypic traits at the whole plant level, such as number of pods in a plant. However, how female reproductive traits contribute to whole plant level traits, and hence to seed yield, has been largely ignored. Here, we describe the combined contribution of 33 phenotypic traits within a B. napus diversity set population and their trade-offs at the whole plant and organ level, along with their interaction with plant level traits. Our results revealed that both Winter OSR (WOSR) and Spring OSR (SOSR); the two more economically important OSR groups in terms of oil production; share a common dominant reproductive strategy for seed yield. In this strategy, the main inflorescence is the principal source of seed yield, producing a good number of ovules, a large number of long pods with a concomitantly high number of seeds per pod. Moreover, we observed that WOSR opted for additional reproductive strategies than SOSR, presenting more plasticity to maximise seed yield. Overall, we conclude that OSR adopts a key strategy to ensure maximal seed yield and propose an ideal ideotype highlighting crucial phenotypic traits that could be potential targets for breeding.


2021 ◽  
Vol 2 (2) ◽  
pp. 041-049
Author(s):  
Djalal Ardjoun Khalil ◽  
Mahamat Ibrahim Souleymane ◽  
Issa Youssouf ◽  
Madjina Tellah ◽  
Mopate Logtene Youssouf ◽  
...  

This work was carried out on the phenotypic characteristics of the Kababich sheep exploited in the peri-urban zone of N'Djamena (Chad). This phenotypic characterization of Kababich sheep should be continued on local breeds for genetic improvement and objective optimization of productivity. The objective of this study is the characterization of phenotypically Kababich sheep exploited in the peri-urban area of ​​N'Djamena-Chad. It was conducted in 39 farms and involved 1035 sheep aged less than one year old. Phenotypic traits were measured according to the guideline defined by FAO. A total of 12 variables were measured including five qualitative and seven quantitative. The results obtained show a positively significant correlation (p> 0.001) between the age of the sheep estimated by the breeder and the dentition (0.83). The ears are drooping and measure 17.90 ± 2.77 cm. The color of the brown dress (fawn) and the smooth and short coat are dominant. The females are matte and the rams of brown dress have horns in the forms of the vestiges. The Kababich is large with a height at the withers of 81.50 ± 9.40 cm, a rump height of 83.24 ± 9.42 cm and a chest circumference of 88.29 ± 9.22 cm. The body is 72.82 ± 9.63 cm long, has a basin width of 19.89 ± 2.53 cm and a chest depth of 40.68 ± 5.16 cm. These measurements show that Kababich is a meat breed by excellence. In addition, the sexual dimorphism very accentuated in this race orients towards a valorization of the young males in the fattening workshops.


2018 ◽  
Vol 16 (4) ◽  
pp. 359-366
Author(s):  
Maria Khalid ◽  
Alvina Gul ◽  
Rabia Amir ◽  
Mohsin Ali ◽  
Fakiha Afzal ◽  
...  

AbstractDrought stress ‘particularly at seedling stage’ causes morpho-physiological differences in wheat which are crucial for its survival and adaptability. In the present study, 209 recombinant inbred lines (RILs) from synthetic wheat (W7984)× ‘Opata’ (also known as SynOpRIL) population were investigated under well-watered and water-limited conditions to identify quantitative trait loci (QTL) for morphological traits at seedling stage. Analysis of variance revealed significant differences (P < 0.01) among RILs, and water treatments for all traits with moderate to high broad sense heritability. Pearson's coefficient of correlation revealed positive correlation among all traits except dry root weight that showed poor correlation with fresh shoot weight (FSW) under water-limited conditions. A high-density linkage map was constructed with 2639 genotyping-by-sequencing markers and covering 5047 cM with an average marker density of 2 markers/cM. Composite interval mapping identified 16 QTL distributed over nine chromosomes, of which six were identified under well-watered and 10 in water-limited conditions. These QTL explained from 4 to 59% of the phenotypic variance. Six QTL were identified on chromosome 7B; three for shoot length under water-limited conditions (QSL.nust-7B) at 64, 104 and 221 cM, two for fresh root weight (QFRW.nust-7B) at 124 and 128 cM, and one for root length (QRL.nust-7B) at 122 cM positions. QFSW.nust-7B appeared to be the most significant QTL explaining 59% of the phenotypic variance and also associated with FSW at well-watered conditions. These QTL could serve as target regions for candidate gene discovery and marker-assisted selection in wheat breeding.


2005 ◽  
Vol 3 (3) ◽  
pp. 373-384 ◽  
Author(s):  
Tania Carolina Camacho Villa ◽  
Nigel Maxted ◽  
Maria Scholten ◽  
Brian Ford-Lloyd

Awareness of the need for biodiversity conservation is now universally accepted, but most often recent conservation activities have focused on wild species. Crop species and the diversity between and within them has significant socioeconomic as well as heritage value. The bulk of genetic diversity in domesticated species is located in traditional varieties maintained by traditional farming systems. These traditional varieties, commonly referred to as landraces, are severely threatened by genetic extinction primarily due to their replacement by modern genetically uniform varieties. The conservation of landrace diversity has been hindered in part by the lack of an accepted definition to define the entity universally recognized as landraces. Without a definition it would be impossible to prepare an inventory and without an inventory changes in landrace constituency could not be recognized over time. Therefore, based on a literature review, workshop discussion and interviews with key informants, common characteristics of landraces were identified, such as: historical origin, high genetic diversity, local genetic adaptation, recognizable identity, lack of formal genetic improvement, and whether associated with traditional farming systems. However, although these characteristics are commonly present they are not always all present for any individual landrace; several crop-specific exceptions were noted relating to crop propagation method (sexual or asexual), breeding system (self-fertilized or cross-fertilized species), length of formal crop improvement, seed management (selection or random propagation) and use. This paper discusses the characteristics that generally constitute a landrace, reviews the exceptions to these characteristics and provides a working definition of a landrace. The working definition proposed is as follows: ‘a landrace is a dynamic population(s) of a cultivated plant that has historical origin, distinct identity and lacks formal crop improvement, as well as often being genetically diverse, locally adapted and associated with traditional farming systems’.


Proceedings ◽  
2020 ◽  
Vol 36 (1) ◽  
pp. 208
Author(s):  
Andrew Borrell ◽  
Barbara George-Jaeggli ◽  
Erik van Oosterom ◽  
Graeme Hammer ◽  
Emma Mace ◽  
...  

Plants are sessile organisms requiring mechanisms that enable them to balance water supply and demand in dry environments. Demand (D) is largely driven by canopy size (transpirational leaf area), although differences in transpiration per unit leaf area also occur. Supply (S) is primarily driven by water capture via the root system. Drought stress can be defined as the situation where supply of water cannot meet demand of the crop, such that water availability is the limiting factor for biomass accumulation. Under such conditions, plants will need to reduce D in order to meet the limited S, access more water to increase S, or increase the efficiency with which water is utilised. We used sorghum, a model C4 crop species, to demonstrate how the stay-green trait can modulate canopy development and root architecture to enhance adaptation. We show how stay-green positively impacts the balance between S and D under post-flowering drought, including insights at the molecular level. We provide examples of how canopy and root traits impact the S/D balance in other cereals under water limitation. For example, on the supply side, the extent of genetic variation for root angle (RA) has been evaluated in sorghum, wheat and barley, and genomic regions associated with RA have been mapped. Furthermore, the relationship between RA and grain yield has been explored in barley and sorghum field trials. The capacity to manipulate components of S and D to optimise the S/D balance should assist crop improvement programs to develop enhanced ideotypes for dry environments.


Agronomy ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1255 ◽  
Author(s):  
Richard Dormatey ◽  
Chao Sun ◽  
Kazim Ali ◽  
Jeffrey A. Coulter ◽  
Zhenzhen Bi ◽  
...  

Sustainable agricultural production is endangered by several ecological factors, such as drought, extreme temperatures, excessive salts, parasitic ailments, and insect pest infestation. These challenging environmental factors may have adverse effects on future agriculture production in many countries. In modern agriculture, conventional crop-breeding techniques alone are inadequate for achieving the increasing population’s food demand on a sustainable basis. The advancement of molecular genetics and related technologies are promising tools for the selection of new crop species. Gene pyramiding through marker-assisted selection (MAS) and other techniques have accelerated the development of durable resistant/tolerant lines with high accuracy in the shortest period of time for agricultural sustainability. Gene stacking has not been fully utilized for biotic stress resistance development and quality improvement in most of the major cultivated crops. This review emphasizes on gene pyramiding techniques that are being successfully deployed in modern agriculture for improving crop tolerance to biotic and abiotic stresses for sustainable crop improvement.


2010 ◽  
Vol 10 ◽  
pp. 1967-1970 ◽  
Author(s):  
Juan Iovanna ◽  
José Luis Neira

Pancreatic cancer (PC) is the fourth leading cause of cancer death, with a median survival of 6 months and a dismal 5-year survival rate of 3–5%, a figure which has remained relatively unchanged over the past 25 years. PC is one of the most difficult diseases to treat due to late initial diagnosis and to resistance to the usual treatments. The presence of occult or clinical metastases at the time of diagnosis, together with the lack of effective chemotherapies, contributes to the high mortality in patients with PC. Its lethal nature stems from its propensity to disseminate rapidly to the lymphatic system and distant organs. Yet, understanding and stopping metastasis may prove to be one of the great potential strategies of treating PC. There is a dire need for the design of new and targeted therapeutic strategies that can overcome the drug resistance and improve the clinical outcome for patients diagnosed with the illness. The knowledge of the molecular aspects of PC is very important, and it is likely to be helpful in the design of newer drugs and the molecular selection of existing agents for targeted therapy. The inhibition of signal pathways can be carried out not only by small molecules, able to bind to selected regions of the target protein, but also by using large molecules as antibodies. The pathway to successful new therapies has been inhibited because of the rapidity with which agents tend to move into randomized, controlled trials without the extensive early testing necessary to optimize treatment regimens. However, lessons have been learned and our collective research effort has generated a substantial platform of knowledge from which further work will spring. The bioavailability of compounds such as antisense oligonucleotides and siRNAs in humans remains a big hurdle, which will require further improvement of gene-delivery strategies. Finally, the long-term goal of the therapy individualization for patients is possible if factors that predict treatment response, such as biological markers, could be determined accurately. These approaches are likely to comprise a mixture of targeted agents in combination with conventional chemotherapy and radiotherapy. For a clinically significant effect to be achieved, treatment strategies should either be in the form of (1) a “horizontal” approach, in which several oncogenic pathways (as those described in this series of reviews) are inhibited; or (2) a “vertical” approach, whereby multiple levels of a major pathway are targeted. Combination therapies, together with improved diagnostic tools and predictive markers, are ultimately desired in order to improve the bleak outlook for patients diagnosed with PC.


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