Diversity of root-endophytic Trichoderma from Malaysian Borneo

Trichoderma species form endophytic associations with plant roots and may provide a range of benefits to their hosts. However, few studies have systematically examined the diversity of Trichoderma species associated with plant roots in tropical regions. During the evaluation of Trichoderma isolates for use as biocontrol agents, root samples were collected from more than 58 genera in 35 plant families from a range of habitats in Malaysian Borneo. Trichoderma species were isolated from surface-sterilised roots and identified following analysis of partial translation elongation factor-1α (tef1) sequences. Species present included Trichoderma afroharzianum, Trichoderma asperelloides, Trichoderma asperellum, Trichoderma guizhouense, Trichoderma reesei, Trichoderma strigosum and Trichoderma virens. Trichoderma asperellum/T. asperelloides, Trichoderma harzianum s.l. and T. virens were the most frequently isolated taxa. tef1 sequence data supported the recognition of undescribed species related to the T. harzianum complex. The results suggest that tropical plants may be a useful source of novel root-associated Trichoderma for biotechnological applications

Whole genome comparison of a large collection of mycobacteriophages reveals a continuum of phage genetic diversity

The bacteriophage population is large, dynamic, ancient, and genetically diverse. Limited genomic information shows that phage genomes are mosaic, and the genetic architecture of phage populations remains ill-defined. To understand the population structure of phages infecting a single host strain, we isolated, sequenced, and compared 627 phages of Mycobacterium smegmatis. Their genetic diversity is considerable, and there are 28 distinct genomic types (clusters) with related nucleotide sequences. However, amino acid sequence comparisons show pervasive genomic mosaicism, and quantification of inter-cluster and intra-cluster relatedness reveals a continuum of genetic diversity, albeit with uneven representation of different phages. Furthermore, rarefaction analysis shows that the mycobacteriophage population is not closed, and there is a constant influx of genes from other sources. Phage isolation and analysis was performed by a large consortium of academic institutions, illustrating the substantial benefits of a disseminated, structured program involving large numbers of freshman undergraduates in scientific discovery

Bioprotection of Acacia mangium using Trichoderma in Malaysia

In Sarawak, Acacia mangium seedlings were inoculated with 50 different Trichoderma isolates obtained from a wide variety of healthy plants in the Planted Forest Zone. The best Trichoderma isolates were selected after 10 trials at the Samarakan Nursery between August 2008 and August 2009. Trichoderma inoculation increased seed germination and seedling establishment (by up to 36%), seedling height and stem diameter (by an average of 25%) and the proportion of healthy seedlings meeting specifications for planting out into the forest by an average of 41 %), compared with untreated controls. Seedlings that received multiple fungicide sprays (standard nursery practice) generally performed slightly less well than the untreated controls. A new Trichoderma inoculum production facility has been built at Samarakan Nursery and Trichoderma inoculation of seedlings will replace the use of fungicide sprays. The economic benefit from increased productivity is estimated to be NZ $2.5 million per year

The seasonality and economic feasibility of cultivating Kappaphycus alvarezii in Panagatan Cays, Caluya, Antique, Philippines

Vegetative thalli of brown and green Kappaphycus alvarezii were cultivated in Panagatan Cays, Caluya, Antique, Philippines, over 60- and 90-day periods using hanging-long line (HL), fixed off-bottom (FB), and hanging long line–fixed off-bottom (HL–FB) methods to determine the daily growth rate and yield. A completely randomized design experiment with six replicates of 5-m line cultivation rope was used in the study. An economic analysis was prepared to determine the viability of the culture systems used. To determine the effect of strain, culture technique, culture days and culture month on the daily growth rate and yield, a combination of these different factors was treated as a single treatment. Results show that at 60-day culture period, daily growth rate and yield in all techniques were lowest in July–August and highest in January–February. Higher growth rate (2.3–4.2% day−1) and yield (3.6–15.8 fresh weight kg m−1 line−1) were obtained from September to February. Significant differences (P<0.05) in growth rate and yield were determined between culture months. At 90-day culture period, there were no significant differences in growth rate and yield between culture months; however, a significant difference was found between culture techniques. The average production (dry weight kg crop−1) of K. alvarezii when grown at 60-day culture period during lean and peak months using HL, FB and HL–FB techniques ranged from 421 to 3310 kg with HL–FB the highest and FB the lowest. Net income, return on investment (ROI) and payback period were all positive during peak months, but negative values were obtained during lean months. Only seaweed grown on HL technique during the peak months at 90-day culture period showed positive income, ROI and payback period. The seasonality of cultivating K. alvarezii is shown in this present study. This paper further shows the best culture technique to be adopted at certain months of the year to produce the highest yield and income

Economic evaluation of grow-out diets for Asian catfish Clarias macrocephalus (Gunther) production

The economic feasibility of four grow-out diets for the Asian catfish Clarias macrocephalus was evaluated on a 1000 m2/crop basis. Hatchery-bred catfish juveniles with mean body weight (MBW) of 3.6 g and mean total length (MTL) of 7.8 cm were stocked at 10 fish/m2. Laboratory-formulated diet with 20% crude protein (CP; Diet 1) resulted in net losses. Laboratory-formulated diet with 34% CP (Diet 2), commercial feed pellet with 29% CP (Diet 3), and a mixed diet of blanched chicken entrails (80%) and rice bran (20%) with 32% CP (Diet 4) gave acceptable return on investment (ROI) of 131-326% and return on operating capital of 52-71%. Culture of Asian catfish fed Diet 2, however, attained higher net profit before tax per 1000 m2/crop, ROI (326%), and has the lowest payback period on investment (0.3 yr) or operating capital (1.4 yr) compared with using Diets 3 and 4. Partial budget analysis showed that higher net benefit can be earned by using Diet 2 as feed for C. macrocephalus compared with using Diet 4. Sensitivity analysis done by increasing in feed cost by 20% and decreasing the selling price of fish by 20% showed that ROI were 107-262% and 46-159%, respectively and return on operating capital of 42-57% and 18-35%, respectively. Payback period on investment were 0.4-0.9 yr and 0.6-1.9 yr, respectively while payback period on operating capital were 1.7-2.2 yr and 2.7-4.7 yr, respectively. Results suggest that C. macrocephalus culture is economically feasible with Diets 2, 3 and 4 as feed but the use of Diet 2 is more profitable

The economic impact of foot and mouth disease control and eradication in the Philippines

The authors evaluate the impact of foot and mouth disease (FMD) and control of the disease in the Philippines using cost-benefit analysis. A scenario in which FMD control is maintained at recent levels with continued presence of the disease is compared to scenarios in which a publicly funded programme achieves eradication by 2005 (current policy objective), 2007 and 2010. Under varying assumptions regarding the development of exports of livestock products following eradication, estimated benefit-cost ratios for the investment in eradication range from 1.6 (2010, no exports) to 12.0 (2005, export of 5,000 tonnes each of low-value and high-value livestock products annually), indicating eradication to be an economically viable investment. The commercial swine sector is estimated to capture 84% of the benefits generated by the public investment in eradication, versus 4% by backyard swine producers. The implications of these results within the context of regional efforts to control FMD in South-East Asia are explored

Enhancing health and vigour of Acacia mangium by nursery inoculation with selected root-endophytic Trichoderma isolates

Root-endophytic Trichoderma isolates were obtained from root samples taken from a wide variety of exceptionally healthy plants in the locality of the Samarakan Nursery, which supplies Acacia mangium seedlings for the Planted Forest Zone (PFZ) in Sarawak, Malaysia. Nursery trials based on approximately 50 single isolates and selected mixtures of these were conducted between 2008-2009. Root-endophytic Trichoderma isolates were inoculated by applying an aqueous suspension of conidia to the growing medium at the time of seed sowing. The most effective treatments resulted in an increase in productivity of >66% in seedlings meeting specification for planting out into the PFZ. These results were validated in large-scale trials conducted in 2010 which showed the same productivity increase from the best isolates. A trial examining the effects of mixing the Trichoderma inoculum into the growing medium before seed sowing compared with application of a conidial suspension (as in the initial trials) demonstrated that both delivery methods gave exactly the same results. Nursery inoculated trees have shown 30% reduction in mortality from diseases and increased growth (up to 15% greater tree height and diameter) in PFZ plantations. Trichoderma inoculation is now standard operating practice at the Samarakan Nursery, replacing multiple sprays of fungicide cocktails and reducing the time taken for seedlings to meet specifications for planting out into the forest from 108 to 90 days. This project is an ongoing collaborative venture between Grand Perfect Sdn Bhd, Sarawak, Malaysia and the Bio-Protection Research Centre, Lincoln University, New Zealand

Development of selected Trichoderma root endophyte treatments to enhance plant health and vigour

Presentation made by Robert Hill at the 13th Annual Trichoderma and Gliocladium Workshop (TG2014), Shanghai, 19-23 October 2014