Presentation on theme: "Charles H. Michler Director, Tropical Hardwood Tree Improvement and Regeneration Center."— Presentation transcript:
Charles H. Michler Director, Tropical Hardwood Tree Improvement and Regeneration Center
Acknowledgments Paul Scowcroft JB Friday Christian Giardina Nick Koch Mike Robinson Travis Idol Nick Dudley Katie Friday James Brewbaker Creighton Litton Bob Masuda Aileen Yeh Cheyenne Perry Tom Baribault Michael Constantinides
Different kinds of koa Canoe logs Elite timber trees Ecological habitat Genetic diversity Adapted to different climates (dry, wet, cold, frost, etc.) Wilt resistant Insect resistant
Population Genetics Taking advantage of genetic variation that exists within a population or between populations to produce trees or stands with desired suite of traits Within Between Match the genetics of the desirable trees with sites where they are well-adapted and then apply good silviculture Productive plantations/natural forests occur when you:
Population Considerations Tend to not want to move populations greater than 1000 ft. in elevation, but this needs to be tested in the case of koa. –Biggest problems occur when you move material from a higher to lower elevation Don’t move populations from areas that have little environmental variation (rainfall, temperature, etc.) to sites that have much variation. Tetraploidy makes it more difficult to predict heritability, but it can be done. Long term retention of seed bank can prevent loss of genetic variation due to high-grading (continually harvest the best trees) and alternate land use.
Sources of Population Variation Mutations –Unique trait appears such as nut shape, branch angle, or figured wood (Natural) Selection of the fittest –Loss of trees that cannot compete Gene flow between populations –We take advantage of this in seed orchards by using parents from different populations
Needs for Genetic Improvement Straightness and lack of forking Volume increase Wood density??? Crown architecture??? Insect tolerance (Acacia psyllid) – Might be accomplished through management Vascular wilt tolerance (Koa wilt) – Often accomplished through resistance of a vector if the disease is mediated in this manner Other traits??
Expectations from Genetic Improvement 2-4%/year gain (20-25% per selection cycle) – Much higher through genomic technologies (if funds are available) Highly heritable – Straightness – Branch angle – Volume – Pest resistance (can be)
Possible limitations to consider Type of pollinators and weight of pollen (short wind driven distance) could limit genetic diversity between separated populations – On the mainland, pollinators in many forested landscapes are becoming or have become absent Seed orchard design still unclear for insect pollinated species (we augment pollinators when they are limiting)
Uses of Vegetative Propagation (grafting, rooted cuttings, tissue culture, air layering, etc.) Preserve important trees Multiplication of important trees for further testing Deploying elite clones to capture maximum genetic gain
Nick Dudley, HARC Development of Wilt resistant koa for Hawai΄i Moderate to high mortality in mid to low elevations Screening families at the seedling stage Developing seed orchard lots to examine durability of field resistance Developing resistant populations across most islands and growing zones Using tissue culture to bank resistant lines
Development and selection of high quality koa using McIntire-Stennis funds at UH-M (Turano, Brewbaker, Friday, Idol, and DeFrank) Evaluate koa progeny for color and figure Develop methods for cloning koa/propagate superior clones Plant clonal orchards at various locations Genotype high quality accessions Determine wood quality of young koa trees Determine ultrastructure of figured wood
KS trees that will be thinned into a seed orchard
After data analysis and thinning (Forest Solutions)………Ready for progeny testing of best families on DHHL land Nick Dudley/Aileen Yeh initiated planting and Oriana Krauss/Keith Woeste measured/analyzed Will analyze wood quality differences among families and also the genetics of seeds in a single pod (one pollen grain may fertilize all eggs in a pod)
High frost tolerance Moderate frost tolerance Low frost tolerance Matching koa seedlings to the correct elevation
SITE LOCATIONS Fig. 1. Site Identification and Elevation. B= Bird Corridor (>7,000 ft ) P= Kipuka Pu’U (6700–6800 ft) H= Hark A (6600–6700 ft) M= Nine Mile (2200–2400 ft) Ni’ihau Kaho’olawe Kaua’i O’ahu Lana’i Moloka’i Hawai’i (Big Island) Maui Hilo Kona Volcanoes National Park B H M P Waimea Kilauea Mauna Kea Kohala Mauna Loa Hualalai Objectives: 1) Estimate variation in genetics between koa populations in various regions of the Big Island, 2) Evaluate genes vital for survival at varied latitudes in a changing climate, 3) Use NexGen sequencing to identify and characterize genes responsible for critical variations in koa populations.
Which genes involved in survival allow certain Acacia koa to survive at higher altitudes while others perish? Upper Range Limit * Koa can grow at lower elevations however, wilt disease has decimated remaining trees M Growth range = 1,000 ft Not adapted = > 1,000 ft north Not adapted = > 1,000 ft south Example: Seedling adaptability range Koa tree survival at varied elevations. Seedpods are usually most viable within 1000 ft of their mother tree. Without koa trees for nesting, endangered birds are pushed towards extinction
Next Generation Sequencing (NGS) Compilation and analysis of NGS datasets. RNA extracted from koa phyllodes was used for NGS to aid in sequence and gene identification. EXAMPLE DATASET Phyllode Bipinnate leaflets
Figure formation in wood. Koa growth is made exceedingly complicated by the differences seen in wood from the sawn trees grown under identical conditions. Which genes are involved in or responsible for the formation of figure in Acacia koa trees ? Why are some “neighbor” trees unexceptional? ElevationPrecipitationInsects Soil content HerbivoresSunlight A B A B A B $4 – $8 bd ft $100 – $150 bd ft Harvest Low Quality Figure High Quality Figure Growth Conditions
Identify genetic variation between various koa populations Evaluate genes vital for survival in a changing climate Assemble the first koa genome sequence available for public use Uncover data useful in koa forest restoration for support of endangered native bird species 'I'iwi (Vestiaria coccinea) 'Akiapola'au (Hemignathus munroi) Koa trees also provide habitat for birds species found only in Hawai’i
Scarification and removal of invasive grasses leads to habitat restoration. Invasive grasses prohibit growth Decreased grass cover improves growth James Leary et al.
Improved Wild tree Proposed Planting Design with Focus on Crop Trees
Lessons Learned: Plantation prescriptions Increase stand density—could be large increase for Koa Mixed tropical hardwood species – Silvicultural trials looking at competition Start planting with focus on end result – Invest in crop trees or invest in the ecology Start with most appropriate seed---the right provenance
What’s needed to be successful Long term commitment (Foundation) Knowledge of basic biology of the species (much to learn) – Flowering, seed biology, physiology Operational and developmental (research) components Land for testing Funds for staff, equipment, infrastructure, and supplies Maintained focus (constant worthy suggestions)