Pimelea is a genus of about 140 plant species, some of which are well-known for causing animal po... more Pimelea is a genus of about 140 plant species, some of which are well-known for causing animal poisoning resulting in significant economic losses to the Australian livestock industry. The main poisonous species/subspecies include Pimelea simplex (subsp. simplex and subsp. continua), P. trichostachya and P. elongata (generally referred to as Pimelea). These plants contain a diterpenoid orthoester toxin, called simplexin. Pimelea poisoning is known to cause the death of cattle (Bos taurus and B. indicus) or weaken surviving animals. Pimelea species are well-adapted native plants, and their diaspores (single seeded fruits) possess variable degrees of dormancy. Hence, the diaspores do not generally germinate in the same recruitment event, which makes management difficult, necessitating the development of integrated management strategies based on infestation circumstances (e.g., size and density). For example, the integration of herbicides with physical control techniques, competitive pa...
Context Avena sterilis subsp. ludoviciana (wild oats) is one of the major winter weeds of the Nor... more Context Avena sterilis subsp. ludoviciana (wild oats) is one of the major winter weeds of the Northern Grains Region of Australia. The abundance of this weed increased dramatically after the adoption of no-tillage conservation agriculture (NTCA). However, information is lacking on the germination characteristics of the two types of seed (i.e. primary and secondary) that it produces. Aims We aimed to determine the light and temperature requirements for germination and the time to germination of primary and secondary seeds of A. ludoviciana, in order to find ways to manage this weed effectively under NTCA systems. Methods Primary and secondary seeds and caryopses from two southern and two northern biotypes were exposed to a range of temperature and light regimes in the glasshouse, and germination was assessed. Key results All biotypes had ∼25% higher germination from primary than secondary seeds. Removing the hull increased caryopsis germination by ∼70%. The use of a light/dark photop...
Coconut Biotechnology: Towards the Sustainability of the ‘Tree of Life’, 2021
The reference citation in the last line has been corrected from (Wilms et al. 2018) to (Wilms et ... more The reference citation in the last line has been corrected from (Wilms et al. 2018) to (Wilms et al. 2019). On Page 75, References section The reference "Wilms H, Rhee JH, Rivera RL et al (2018) Developing coconut cryopreservation protocols and establishing cryo-genebank at RDA; a collaborative project between RDA and Bioversity International. III international symposium on plant cryopreservation 1234, pp 343-348" has now been corrected to "Wilms H, Rhee JH, Rivera RL et al (2019) Developing coconut cryopreservation protocols and establishing cryo-genebank at RDA; a collaborative project between RDA and Bioversity International. III international symposium on plant cryopreservation 1234, pp 343-348".
Invasion, spread and establishment of invasive alien species in a new environment causes serious ... more Invasion, spread and establishment of invasive alien species in a new environment causes serious ecosystem perturbation and native species extinctions. The problem is further aggravated under climate change as some invasive alien species perform better under elevated temperature and carbon dioxide regimes. Currently unsuitable regions such as high-altitude areas and mountains are likely to become more suited to invasion under future climatic conditions. We have modelled the distribution of one of the most invasive alien species, parthenium weed ( Parthenium hysterophorus L.) which is rapidly colonizing different parts of Bhutan. We have implemented ensemble modelling approach using the BIOMOD2 package in R environment. Under current climate scenario, about 2.83% (1, 099.01 km 2 ) of the country’s total area is predicted to be suitable for parthenium weed invasion, covering 17 out of the 20 districts in Bhutan. Under future climate scenarios, the highest suitability is predicted unde...
Parthenium weed: biology, ecology and management, 2019
This chapter deals with various human and animal health impacts of pathenium weed (Parthenium hys... more This chapter deals with various human and animal health impacts of pathenium weed (Parthenium hysterophorus). Diseases caused by the weed include dermatitis, rhinitis, asthma and atopic dermatitis. The detrimental health effects of parthenium weed are attributed to the sesquiterpene lactones and in particular parthenin in the plant which are toxic to farm animals and responsible for allergic diseases in humans. As parthenium weed continues to spread through Africa and Asia, information needs to be collected from those countries which have recently been invaded and those that are proximal to infestations. The collection of data and the monitoring of parthenium invasion may ultimately be used to manage both the spread and impact of the weed.
In situ conservation of coconut germplasm refers to the maintenance of coconut genetic diversity ... more In situ conservation of coconut germplasm refers to the maintenance of coconut genetic diversity in the agroecosystems where it has evolved. Ex situ conservation comprises all coconut germplasm currently maintained as living trees in field genebanks, screen houses, and elsewhere beyond their host agroecosystems. Ex situ conservation includes in vitro conservation, as well as cryopreservation of pollen, embryos, and embryogenic callus. This chapter presents the variety of existing approaches to conserve coconut germplasm, together with a prospective approach assessing how farmers could better benefit from the advances recently achieved in coconut biotechnology for the sustainable conservation of coconut diversity. This chapter also emphasizes biological and sociological constraints jeopardizing conservation. Ex situ coconut conservation is facing a crisis. Among the 24 registered coconut genebanks, at least 16, including 3 out of the 5 international genebanks, do not have enough capa...
Coconut (Cocos nucifera L) plays an important role in the socio-economic life of many millions of... more Coconut (Cocos nucifera L) plays an important role in the socio-economic life of many millions of people in the tropical regions of the world. However, the genetic diversity of this species is being dramatically decreased by diseases, natural disasters and through land cleaning for the planting of the so called 'more valuable' crops. Coconut seed cannot be conserved by normal means as it is big and sensitive to drying (recalcitrant). Cryopreservation is an alternative conservation approach but as yet, this method is still poorly developed for coconut. Thus, there is a need to develop a new, more reliable cryopreservation protocol for this crop. A new cryopreservation protocol, based on a rapid tissue desiccation step was developed to produce a high plant recovery rate after cryopreservation. Embryos from four coconut cultivars (Malayan Yellow Dwarf - MYD, Nias Yellow Dwarf - NYD, Nias Green Dwarf and Sagerat Orange Dwarf) were rapidly desiccated for 8 hours (water content de...
Abstract To elucidate the response of oxidative metabolism, triggered by elevated ammonium (NH4+)... more Abstract To elucidate the response of oxidative metabolism, triggered by elevated ammonium (NH4+) concentrations, on root growth of wheat seedlings, Yumai 49 (NH4+-tolerant) and Lumai 15 (NH4+-sensitive) cultivars were supplied with either 5.0 mmol L−1 NH4+-N (EAC) or 5.0 mmol L−1 NO3–-N (CON) under hydroponic conditions. Root growth in both cultivars was significantly reduced under EAC, and the negative effect was greater in Lumai 15. EAC enhanced the activities of monodehydroascorbate reductase and dehydroascorbate reductase in the roots of both cultivars, while it decreased ascorbic acid (ASA) content and GDP-mannose pyrophosphorylase (GMPase) activity at the 12th day after treatment in Lumai 15 by 62.0 and 71.4%; and in Yumai 49 by 38.8 and 62.2%, respectively, indicating that the regeneration of ASA was increased, but the biosynthesis of ASA was reduced under EAC treatment. Moreover, EAC increased DHA/ASA, reactive oxygen species (ROS), and malondialdehyde contents, as well as antioxidant enzyme activities in the roots of both cultivars. Relatively greater increases in ROS and soluble sugar, and lower antioxidant enzyme activities in Lumai 15 indicate severe disruption of oxidative metabolism when compared to Yumai 49. Results reveal that the reduction of ASA biosynthesis via decreased GMPase activity under the EAC condition probably acts as a trigger for accumulated ROS and imbalanced redox status, resulting in root growth inhibition during wheat seedling growth stage. Yumai 49, being an NH4+ -tolerant cultivar, had the stronger capacity to protect itself from oxidative stress, which allowed it to retain a lower DHA to ASA ratio by maintaining a better redox homeostasis than could be maintained in the NH4+ -sensitive cultivar Lumai 15.
Coconut Biotechnology: Towards the Sustainability of the ‘Tree of Life’, 2020
It has been estimated that around one in ten of the human population is connected directly with c... more It has been estimated that around one in ten of the human population is connected directly with coconut production and the processing, trade, and retail distribution of the diversity of its products. Industry planners, nationally and internationally, require information on the principal sources of production, and consumption, locally and through world trade, as well as awareness of the urgency for replanting and the potential means to rapidly achieve this. The production base of the coconut industry is shown to be currently stable, but the advanced age of a high proportion of the palms foreshadows an accelerating decline in productivity unless renewal begins immediately. The purpose of this book is to provide a road map for replanting by identifying up-to-date knowledge on the ecology of the coconut, its management needs, and above all the choice of genotypes possessing traits that will advance adaptation and potential productivity beyond that presently achieved by the old generation of palms needing to be replaced. Recent advances in biotechnology, offering the possibility for a new way to conserve germplasm by cryopreservation, the large-scale cloning of coconut, and the detailed understanding of coconut genetics, are shown here. Taken together, they present a great opportunity to deliver superior plantlets and seedlings in an adequate quantity to specific regions. The complexities and challenges of selecting the best possible genotype for a given location are shown to be a pressing need requiring urgent attention.
This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
Pimelea is a genus of about 140 plant species, some of which are well-known for causing animal po... more Pimelea is a genus of about 140 plant species, some of which are well-known for causing animal poisoning resulting in significant economic losses to the Australian livestock industry. The main poisonous species/subspecies include Pimelea simplex (subsp. simplex and subsp. continua), P. trichostachya and P. elongata (generally referred to as Pimelea). These plants contain a diterpenoid orthoester toxin, called simplexin. Pimelea poisoning is known to cause the death of cattle (Bos taurus and B. indicus) or weaken surviving animals. Pimelea species are well-adapted native plants, and their diaspores (single seeded fruits) possess variable degrees of dormancy. Hence, the diaspores do not generally germinate in the same recruitment event, which makes management difficult, necessitating the development of integrated management strategies based on infestation circumstances (e.g., size and density). For example, the integration of herbicides with physical control techniques, competitive pa...
Context Avena sterilis subsp. ludoviciana (wild oats) is one of the major winter weeds of the Nor... more Context Avena sterilis subsp. ludoviciana (wild oats) is one of the major winter weeds of the Northern Grains Region of Australia. The abundance of this weed increased dramatically after the adoption of no-tillage conservation agriculture (NTCA). However, information is lacking on the germination characteristics of the two types of seed (i.e. primary and secondary) that it produces. Aims We aimed to determine the light and temperature requirements for germination and the time to germination of primary and secondary seeds of A. ludoviciana, in order to find ways to manage this weed effectively under NTCA systems. Methods Primary and secondary seeds and caryopses from two southern and two northern biotypes were exposed to a range of temperature and light regimes in the glasshouse, and germination was assessed. Key results All biotypes had ∼25% higher germination from primary than secondary seeds. Removing the hull increased caryopsis germination by ∼70%. The use of a light/dark photop...
Coconut Biotechnology: Towards the Sustainability of the ‘Tree of Life’, 2021
The reference citation in the last line has been corrected from (Wilms et al. 2018) to (Wilms et ... more The reference citation in the last line has been corrected from (Wilms et al. 2018) to (Wilms et al. 2019). On Page 75, References section The reference "Wilms H, Rhee JH, Rivera RL et al (2018) Developing coconut cryopreservation protocols and establishing cryo-genebank at RDA; a collaborative project between RDA and Bioversity International. III international symposium on plant cryopreservation 1234, pp 343-348" has now been corrected to "Wilms H, Rhee JH, Rivera RL et al (2019) Developing coconut cryopreservation protocols and establishing cryo-genebank at RDA; a collaborative project between RDA and Bioversity International. III international symposium on plant cryopreservation 1234, pp 343-348".
Invasion, spread and establishment of invasive alien species in a new environment causes serious ... more Invasion, spread and establishment of invasive alien species in a new environment causes serious ecosystem perturbation and native species extinctions. The problem is further aggravated under climate change as some invasive alien species perform better under elevated temperature and carbon dioxide regimes. Currently unsuitable regions such as high-altitude areas and mountains are likely to become more suited to invasion under future climatic conditions. We have modelled the distribution of one of the most invasive alien species, parthenium weed ( Parthenium hysterophorus L.) which is rapidly colonizing different parts of Bhutan. We have implemented ensemble modelling approach using the BIOMOD2 package in R environment. Under current climate scenario, about 2.83% (1, 099.01 km 2 ) of the country’s total area is predicted to be suitable for parthenium weed invasion, covering 17 out of the 20 districts in Bhutan. Under future climate scenarios, the highest suitability is predicted unde...
Parthenium weed: biology, ecology and management, 2019
This chapter deals with various human and animal health impacts of pathenium weed (Parthenium hys... more This chapter deals with various human and animal health impacts of pathenium weed (Parthenium hysterophorus). Diseases caused by the weed include dermatitis, rhinitis, asthma and atopic dermatitis. The detrimental health effects of parthenium weed are attributed to the sesquiterpene lactones and in particular parthenin in the plant which are toxic to farm animals and responsible for allergic diseases in humans. As parthenium weed continues to spread through Africa and Asia, information needs to be collected from those countries which have recently been invaded and those that are proximal to infestations. The collection of data and the monitoring of parthenium invasion may ultimately be used to manage both the spread and impact of the weed.
In situ conservation of coconut germplasm refers to the maintenance of coconut genetic diversity ... more In situ conservation of coconut germplasm refers to the maintenance of coconut genetic diversity in the agroecosystems where it has evolved. Ex situ conservation comprises all coconut germplasm currently maintained as living trees in field genebanks, screen houses, and elsewhere beyond their host agroecosystems. Ex situ conservation includes in vitro conservation, as well as cryopreservation of pollen, embryos, and embryogenic callus. This chapter presents the variety of existing approaches to conserve coconut germplasm, together with a prospective approach assessing how farmers could better benefit from the advances recently achieved in coconut biotechnology for the sustainable conservation of coconut diversity. This chapter also emphasizes biological and sociological constraints jeopardizing conservation. Ex situ coconut conservation is facing a crisis. Among the 24 registered coconut genebanks, at least 16, including 3 out of the 5 international genebanks, do not have enough capa...
Coconut (Cocos nucifera L) plays an important role in the socio-economic life of many millions of... more Coconut (Cocos nucifera L) plays an important role in the socio-economic life of many millions of people in the tropical regions of the world. However, the genetic diversity of this species is being dramatically decreased by diseases, natural disasters and through land cleaning for the planting of the so called 'more valuable' crops. Coconut seed cannot be conserved by normal means as it is big and sensitive to drying (recalcitrant). Cryopreservation is an alternative conservation approach but as yet, this method is still poorly developed for coconut. Thus, there is a need to develop a new, more reliable cryopreservation protocol for this crop. A new cryopreservation protocol, based on a rapid tissue desiccation step was developed to produce a high plant recovery rate after cryopreservation. Embryos from four coconut cultivars (Malayan Yellow Dwarf - MYD, Nias Yellow Dwarf - NYD, Nias Green Dwarf and Sagerat Orange Dwarf) were rapidly desiccated for 8 hours (water content de...
Abstract To elucidate the response of oxidative metabolism, triggered by elevated ammonium (NH4+)... more Abstract To elucidate the response of oxidative metabolism, triggered by elevated ammonium (NH4+) concentrations, on root growth of wheat seedlings, Yumai 49 (NH4+-tolerant) and Lumai 15 (NH4+-sensitive) cultivars were supplied with either 5.0 mmol L−1 NH4+-N (EAC) or 5.0 mmol L−1 NO3–-N (CON) under hydroponic conditions. Root growth in both cultivars was significantly reduced under EAC, and the negative effect was greater in Lumai 15. EAC enhanced the activities of monodehydroascorbate reductase and dehydroascorbate reductase in the roots of both cultivars, while it decreased ascorbic acid (ASA) content and GDP-mannose pyrophosphorylase (GMPase) activity at the 12th day after treatment in Lumai 15 by 62.0 and 71.4%; and in Yumai 49 by 38.8 and 62.2%, respectively, indicating that the regeneration of ASA was increased, but the biosynthesis of ASA was reduced under EAC treatment. Moreover, EAC increased DHA/ASA, reactive oxygen species (ROS), and malondialdehyde contents, as well as antioxidant enzyme activities in the roots of both cultivars. Relatively greater increases in ROS and soluble sugar, and lower antioxidant enzyme activities in Lumai 15 indicate severe disruption of oxidative metabolism when compared to Yumai 49. Results reveal that the reduction of ASA biosynthesis via decreased GMPase activity under the EAC condition probably acts as a trigger for accumulated ROS and imbalanced redox status, resulting in root growth inhibition during wheat seedling growth stage. Yumai 49, being an NH4+ -tolerant cultivar, had the stronger capacity to protect itself from oxidative stress, which allowed it to retain a lower DHA to ASA ratio by maintaining a better redox homeostasis than could be maintained in the NH4+ -sensitive cultivar Lumai 15.
Coconut Biotechnology: Towards the Sustainability of the ‘Tree of Life’, 2020
It has been estimated that around one in ten of the human population is connected directly with c... more It has been estimated that around one in ten of the human population is connected directly with coconut production and the processing, trade, and retail distribution of the diversity of its products. Industry planners, nationally and internationally, require information on the principal sources of production, and consumption, locally and through world trade, as well as awareness of the urgency for replanting and the potential means to rapidly achieve this. The production base of the coconut industry is shown to be currently stable, but the advanced age of a high proportion of the palms foreshadows an accelerating decline in productivity unless renewal begins immediately. The purpose of this book is to provide a road map for replanting by identifying up-to-date knowledge on the ecology of the coconut, its management needs, and above all the choice of genotypes possessing traits that will advance adaptation and potential productivity beyond that presently achieved by the old generation of palms needing to be replaced. Recent advances in biotechnology, offering the possibility for a new way to conserve germplasm by cryopreservation, the large-scale cloning of coconut, and the detailed understanding of coconut genetics, are shown here. Taken together, they present a great opportunity to deliver superior plantlets and seedlings in an adequate quantity to specific regions. The complexities and challenges of selecting the best possible genotype for a given location are shown to be a pressing need requiring urgent attention.
This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
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