Toxic effects of Pb2+ on growth of cowpea (Vigna unguiculata)

A concentration as low as 1 μM lead (Pb) is highly toxic to plants, but previous studies have typically related plant growth to the total amount of Pb added to a solution. In the present experiment, the relative fresh mass of cowpea (Vigna unguiculata) was reduced by 10% at a Pb2+ activity of 0.2 μM for the shoots and at a Pb2+ activity of 0.06 μM for the roots. The primary site of Pb2+ toxicity was the root, causing severe reductions in root growth, loss of apical dominance (shown by an increase in branching per unit root length), the formation of localized swellings behind the root tips (due to the initiation of lateral roots), and the bending of some root tips. In the root, Pb was found to accumulate primarily within the cell walls and intercellular spaces.

Development and Accreditation of an Applied Climate Education Unit for Sustainable Land Use in Australia

In recent years, there have been significant developments in climate science relevant to agriculture and natural resource management. Assessing impacts of climate variability and use of seasonal climate forecasts have become increasingly important elements in the management "toolkit" for many Australian farmers. Consideration of climate change further increases the need for improved management strategies. While climate risk extension activities have kept pace with advances in climate science, a national review of the Vocational Education and Training system in Australia in relation to "weather and climate" showed that these topics were "poorly represented" at the management level in the Australian Qualifications Framework, and needed increased emphasis. Consequently, a new Unit of Competency concerning management of climatic risk was developed and accredited to address this deficiency. The objective of the unit was to build knowledge and skills for better management of climate variability via the elements of surveying climatic and enterprise data; analysing climatic risks and opportunities; and developing climatic risk management strategies. This paper describes establishment of a new unit for vocational education that is designed to harness recent developments in applied climate science for better management of Australia's highly variable climate. The main benefits of the new unit of competency, "Developing climatic risk management strategies,"were seen as improving decisions in climate and agriculture, and reducing climate risk exposure to enhance sustainable agriculture. The educational unit is now within the scope of agricultural colleges, universities, and registered training organisations as an accredited unit.

Radish leaves and radish roots: are we eating the right part for cancer prevention?

Radishes are most commonly consumed as a root vegetable, although radish leaves are occasionally used in salads and cooking. While both the radish root and shoot contain glucosinolates with anti-cancer potential, the glucosinolate profile of the root and the shoot are very different. Whereas the root contains mainly glucodehydroerucin (2.8 mol/gFW) (also known as glucoraphasatin), the main glucosinolate components of the shoot are glucoraphanin (2.8 mol/gFW) and glucoraphenin (2.1 mol/gFW). Upon hydrolysis, the latter glucosinolates produce sulforaphane and sulforaphene respectively, both potent inducers of mammalian phase 2 enzymes. Previously, radishes have been dismissed as having minimal anti-cancer potential based on studies with radish roots. However, depending on the cultivar, radish shoots can have up to 45 times the capacity of roots to induce phase 2 enzymes. In fact, shoots of a number of radish cultivars (eg. 'Black Spanish') have similar or greater anti-cancer potential than broccoli florets, a vegetable that has received considerable interest in this area.

Genetic Structure of Cochliobolus sativus Populations Sampled from Roots and Leaves of Barley and Wheat in North Dakota

Common root rot (CRR) and spot blotch, caused by Cochliobolus sativus (Ito and Kurib.) Drechsl. ex Dast., are important diseases of barley (Hordeum vulgare L.) and wheat (Triticum aestivum L.) worldwide. However, the population biology of C. sativus is still poorly understood. In this study, the genetic structure of three C. sativus populations, consisting of isolates sampled respectively from barley leaves (BL), barley roots (BR) and wheat roots (WR) in North Dakota, was analysed with amplified fragment length polymorphism (AFLP) markers. A total of 127 AFLP loci were generated among 208 C. sativus isolates analysed with three primer combinations. Gene diversity (H = 0.277-0.335) were high in all three populations. Genetic variation among C. sativus individuals within population accounted for 74%, whereas 26% of the genetic variation was explained among populations. Genetic differentiation was high (empty set PT = 0.261, corrected G ''(st)= 0.39), whereas gene flow (Nm) ranged from 1.27 to 1.56 among the three populations analysed. The multilocus linkage disequilibrium (LD) ((r) over bard = 0.0760.117) was moderate in C. sativus populations. Cluster analyses indicate that C. sativus populations differentiated according to the hosts (barley and wheat) and tissues (root and leaf) although generalists also exist in North Dakota. Crop breeding may benefit from combining genes for resistance against both specialists and generalists of C. sativus.

Genetic Structure of Cochliobolus sativus Populations Sampled from Roots and Leaves of Barley and Wheat in North Dakota

Common root rot (CRR) and spot blotch, caused by Cochliobolus sativus (Ito and Kurib.) Drechsl. ex Dast., are important diseases of barley (Hordeum vulgare L.) and wheat (Triticum aestivum L.) worldwide. However, the population biology of C. sativus is still poorly understood. In this study, the genetic structure of three C. sativus populations, consisting of isolates sampled respectively from barley leaves (BL), barley roots (BR) and wheat roots (WR) in North Dakota, was analysed with amplified fragment length polymorphism (AFLP) markers. A total of 127 AFLP loci were generated among 208 C. sativus isolates analysed with three primer combinations. Gene diversity (H = 0.277-0.335) were high in all three populations. Genetic variation among C. sativus individuals within population accounted for 74%, whereas 26% of the genetic variation was explained among populations. Genetic differentiation was high (empty set PT = 0.261, corrected G ''(st)= 0.39), whereas gene flow (Nm) ranged from 1.27 to 1.56 among the three populations analysed. The multilocus linkage disequilibrium (LD) ((r) over bard = 0.0760.117) was moderate in C. sativus populations. Cluster analyses indicate that C. sativus populations differentiated according to the hosts (barley and wheat) and tissues (root and leaf) although generalists also exist in North Dakota. Crop breeding may benefit from combining genes for resistance against both specialists and generalists of C. sativus.