Massey Documents by Type
Permanent URI for this communityhttps://mro.massey.ac.nz/handle/10179/294
Browse
7 results
Search Results
Item Vigour assessment in Pinus radiata D. Don seeds : a thesis presented in partial fulfilment of the requirements for the degree of Master of Agricultural Science in seed technology at Massey University, Palmerston North, New Zealand(Massey University, 1990) Kartiko, Hero Dien P. (Hero Dien Pancang)The sensitivity and/or predictivity of various vigour test methods (which include conductivity, tetrazolium, x-ray contrast, seedling growth, controlled deterioration, complex stressing vigour, and low temperature/osmotic stress tests) for prepared lots of Pinus radiata seeds were investigated in this study. The best tests were the controlled deterioration test with two days aging treatment (CD2d) test), the prechilled seedling growth test (SG+pr test), and the complex stressing vigour test (CSV test). These were then further investigated to evaluate their ability to predict the performance of different seed lots at the Forest Research Institute (FRI) nursery, Rotorua. The CD2d, SG + pr and CSV tests showed good correlation, especially with percentage of plan table seedlings at the FRI nursery. In addition, these tests seem to have met most of the AOSA's (1983) criteria for a practical vigour testing, as they are simple and can be done in a relatively short period of time. For application purposes, it is suggested that the test parameters which gave the highest correlation coefficient value with percentage of plan table seedlings in the nursery should be used as a reliable measurement. Therefore, percentage normal seedlings should be used in either the CD2d or the CSV test, whereas T50 radicle emergence seems more predictive in the SG+pr test. For application in other nurseries, these tests may still be valid, especially if pre-sowing treatment and nursery conditions are about the same as in the FRI nursery. If conditions do differ, however, the CD2d and SG + pr tests are more likely to be useful than the CSV test. This hypothesis is based on the fact that the CD2d and SG + pr tests also gave good correlations with the glasshouse (optimum conditions) and winter field tests (sub-optimum conditions). In contrast, there was no significant correlation given by the CSV test in relation to the glasshouse and winter field tests. Seed weight had a significant effect on seedling dry weight and Tso radicle emergence if there was a large seed weight variation between seed lots. In this case, generally heavier seeds had better performance than the lighter ones. If there was only small variation in overall seed weight among seed lots, however, the important effects of individual differences in seed weights were masked. The direction of further studies would seem to be to evaluate the reproducibility of correlation coefficient values and regression equations by the CD2d, SG + pr and CSV tests in the same nursery site over several sowings. Additionally, vigour test evaluation using seed lots from individual clones would also seem to be important.Item A study of the relationship between seed quality and commercial sprouting quality of green gram (Vigna mungo L. Hepper) and black gram (Vigna radiata L. Wilczek) : a thesis presented in partial fulfilment of the requirement for the degree of Master of Applied Science in Seed Technology at Massey University, Palmerston North, New Zealand(Massey University, 1998) DeFilippi, Joanne MareeStandard seed quality tests (seed moisture content, thousand seed weight, topographical tetrazolium, germination and seedling evaluation); vigour tests (accelerated ageing, conductivity, rate of germination and uniformity of germination) and industry based tests (oversoaks and sprouters) were evaluated for their ability to rank eight black gram (Vigna mungo L. Hepper) seed lots and seven green gram (Vigna radiata L. Wilczek) seed lots for the purpose of commercial sprouting. Each seed lot was sprouted using simulated commercial conditions (19°C water temperature; 20°C cabin temperature; dark; 5 days). Seed lots which performed well under these small scale commercial production (SSCP) conditions, in terms of total fresh yield and healthy sprout yield, were considered to be the best quality seed lots. All tests were able to significantly determine differences among seed lots within each species. Linear regression analysis indicated that interim germination (R² = 79.1%), final germination (R² = 76.3%), seed moisture content (SMC) (R² = 63.7%) and oversoak sprouters (R² = 60.6%) were significantly related to total fresh yield in green gram seed lots only. No other significant linear relationships were found for either green gram or black gram. Incorporating interim germination, final germination, SMC and oversoak sprouters in a multivariate analysis reduced the level of unexplained variation in green gram total sprout yield. The best combination was interim germination and oversoak sprouters (R² = 84.2%); Y = 9.1(%interim germination) - 8.1 (oversoak %sprouters) + 731.4. Very similar to this was the combination of final germination and SMC (R² = 83.8%); Y = 4.7(%final germination) + 15.3(%SMC) + 165.4. The reason for the differing responses of black gram and green gram was not explained, but both genetic variation and differences in environment during seed development and handling prior to testing are likely causes. It was not possible to use any individual or combination of tests to predict sprouting performance for green or black gram with the accuracy the sprouting industry would require. However, the results have shown that it will be possible to eliminate many of the seed quality tests examined from further research. Refinement of test procedures for the relevant standard and industry based tests will be required to provide the accurate seed testing regime needed by the sprouting industry.Item Optimising the seed production cycle of Delphinium elatum L. : a thesis presented in partial fulfilment of the requirements for the degree of Master of Science in Plant Biology at Massey University, Palmerston North(Massey University, 2005) Bedford, KatharineDelphinium elatum L. (Ranunculaceae) hybrids are developed by Dowdeswell's Delphiniums located at 692 Brunswick Road. Wanganui (www.delphinium.co.nz), who grow delphiniums for seed export. Development of new cultivars is important for commercial purposes, and requires development of high quality breeds. The main objectives of this study were to determine reasons for variable seed set and low germination in commercial D. elatum hybrids and determine optimal parameters for seed germination and storage. Seed set was investigated by examining pollen viability, carpel structure, and pollen tube growth in vitro and in vivo. Seed structure was determined by paraffin embedding and sectioning of seeds. Results investigating variable seed set were inconclusive. Seed set is limited by pollen viability and age. Pollen viability is low (below 50%) in most cultivars, and pollen tubes growth rate is variable between cultivars and individual pollen grains. Ovule development showed no abnormalities. Germination-promoting treatments were used to improve germination in D. elatum. Stratification (5°C) and application of gibberellic acid both improved germination in D. elatum cultivars. Chilling at 5°C reduced germination time in all cultivars, and increased total germination in cv. LB01130x. Storage trials were carried out for 12 months, with seeds stored at room temperature or 5°C in open and closed, water impermeable, aluminium bags. Storage trials determined that at low temperature storage (5°C) seed germinability is retained for up to 12 month. Storage at room temperature leads to seed deterioration and viability loss. Application of GA3 improved germination in seed stored at 5°C.Item Viability of endophytic fungus in different perennial ryegrass (Lolium perenne) varieties kept in different storage conditions : a thesis presented in partial fulfilment of the requirements for the degree of Master of Science at Massey University, Manawatū, New Zealand(Massey University, 2017) Kitson, Elizabeth RoseEpichloë endophytes form symbiotic relationships with cool-season grasses of the Pooideae family and are known to synthesise a range of bio-protective alkaloids. These alkaloids can provide the grass host with benefits for greater survival including; deterrence of herbivorous pests, increased persistence, better livestock health and protection from abiotic stressors. The commercialisation of novel endophytes is on the increase, and it is important to ensure the survival of the endophyte is maintained so their benefits can be realised. This study examined the effects of different storage conditions on the viability of three commercial novel endophytes (AR1, AR37 and NEA2/6) and one pre-commercial novel endophyte (815). The different storage conditions were the top of a warehouse, the bottom of a warehouse and a temperature and humidity controlled cool store to simulate current commercial seed storage environments. The viability of different endophytes decreases independently of grass seed germination (p = NS) however there are many factors influencing the endophyte survival. Over the one year storage period there were significant interactions between endophyte x ploidy (host), endophyte x location and endophyte x ploidy (host) x location. The pre-commercial endophyte, 815, had the largest reduction in viable endophyte when stored outside of the controlled cool store dropping 70 percentage points at the top of the warehouse, compared with AR37 (12 percentage points), AR1 (16 percentage points), and NEA2/6 (46 percentage points) (p<.001, LSD = 15.9). In the cool store there was no significant decrease in any of the treatments. As more novel endophyte/grass combinations are released for commercial sale it is important to test each for compatibility and performance post-storage. The results of this study recommend controlled low-temperature, low-humidity storage to maintain endophyte viability. Keywords: Endophyte, Epichloë, perennial ryegrass, Lolium perenne, storageItem Seed storage behaviour of New Zealand's threatened vascular plants : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy (PhD) in Horticultural Science at Massey University, Palmerston North, New Zealand(Massey University, 2013) Park, Myoung JooAt least 38% of New Zealand’s approximately 2300 vascular plant taxa (species and subspecies) are threatened in situ and are vulnerable to extinction. It has become increasingly important that a number of different complementary conservation approaches and methods are used to insure against this loss of species. However, limitations exist for the development of ex situ storage techniques due to a lack of basic research on seed biology, including seed storage behaviour and germination requirement of many rare and threatened species. Seven New Zealand native species, Carmichaelia williamsii, Clianthus puniceus, Clianthus maximus, Hibiscus diversifolius, Myosotidium hortensium, Tecomanthe speciosa and Dysoxylum spectabile are a priority for investigation for ex situ conservation strategies because of their conservation priority and lack of corresponding techniques for their long term ex situ conservation. This study reports on seed storage behaviour, dormancy mechanisms and potential ex situ conservation strategy including conventional seed storage and cryopreservation of these New Zealand indigenous species to facilitate germplasm storage. C. williamsii, C. puniceus, C. maximus, H. diversifolius, M. hortensium and T. speciosa were found to tolerate low seed moisture content (<5%) and thus can potentially be stored for long periods under conventional seed bank conditions, whilst Dysoxylum spectabile displayed essentially recalcitrant seed storage behaviour i.e. loss of viability when desiccated below 25%. There is a need to consider alternative ex situ conservation strategies, such as cryopreservation, to conserve this species. Both C. maximus and M. hortensium displayed ‘essentially’ orthodox seed storage behaviour i.e. tolerance to desiccation and low temperature. However, viability of M. hortensium seeds declined after 12 months in all storage treatments and may be defined as sub-orthodox. This study demonstrated embryonic axis cryopreservation in D. spectabile using a method based on rapid desiccation, encapsulation-dehydration and vitrification. This is the first report of the successful cryopreservation of New Zealand native species. In D. spectabile, encapsulation-dehydration or vitrification-based cryopreservation gave higher levels of survival (20%) than rapid desiccation cryopreservation. However, further optimisation of the protocol for plantlet recovery is needed to improve efficiency before it can be considered suitable for conservation purposes. It is essential to understand dormancy mechanisms and to have effective methods of seed germination so seed banks can increase their efficiency and enhance their role in biodiversity conservation. However, germination requirements for many native species are either incomplete or not available. Unlike T. speciosa and D. spectabile, seeds of C. williamsii, C. puniceus, C. maximus, H. diversifolius and M. hortensium were dormant and that this dormancy was found to be of function of the seed coat. Dormancy in C. williamsii, C. puniceus, C. maximus and H. diversifolius is a result of the seed coat preventing water uptake by the dry seed. While physical constraint of embryo growth by the seed coat is the cause of dormancy in M. hortensium seeds.Item A study of seed development, seed coat structure, and seed longevity in "Grasslands Pawera" red clover (Trifolium pratense L.) : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy at Massey University, New Zealand(Massey University, 1978) Pe, Win'Grasslands Pawera' tetraploid red clover is an important agricultural legume through its agronomic roles in soil enrichment by nitrogen fixation and the production of high yields of quality herbage. Since this cultivar was only recently released in New Zealand, many of its agronomic aspects, and particularly those relating to seed production are still not fully understood. The present study was conducted to investigate the pattern of seed development, attainment of seed quality components, time of harvesting, cell structure in the seed coat, hardseededness and related problems, and the longevity and germination characteristics of seeds buried in the soil. Peak flowering date varies with time of sowing and climatic conditions, a sufficiently large number of effective bee pollinators (Bombus species) being essential during the flowering period for successful seed production. The pattern of seed development in 'Pawera' red clover is similar to that of its diploid counterparts and may be divided into three distinct stages. The first stage lasts for 10 days after pollination. The second stage occupies a period of 16 days, and the third stage takes a further 10-14 days. Seed dry weight is maximal 26 days after pollination (physiological maturity). Maximum seed viability is attained 22 to 26 days after pollination. Therefore if seed is harvested during the third or ripening stage, seed quality components such as viability, seedling vigour, seed weight, and storage life will not be adversely affected. The correct time of harvesting can be decided by using seed coat colour and seed moisture content as seed maturity indices. Generally the sequences of both embryo and endosperm development in 'Pawera' red clover show close similarity to some other Trifolium species. The processes of cell degeneration and differentiation occur throughout the seed developmental period. Cell structure in the seed coat is also similar to corresponding structures in the testa of other small-seeded legumes. The present investigation highlights the relationship between individual seed coat structures and their respective role in affecting seedcoat permeability and impermeability mechanisms. The results fail to implicate the micropyle or hilum as permeable sites on the seed coat. In originally permeable seeds, water conduction occurs at random sites on the seed coat. However, when a hard seed is softened by mechanical impaction or under natural environmental conditions, the strophiole is the only initial permeable site on the testa. Observations in the present study have clearly implicated the cell structure of the strophiolar region as a unique and most sensitive area of the seed coat. The findings of the present study suggest that the rate of breakdown of hardseededness varies inversely with the depth of seed burial. Seed samples containing mature seeds maintain their viability in the soil longer than immature seeds. The rapid depletion of seed numbers in the soil is mainly due to germination in situ. Certain proportions of the seed population persist in the soil for extended periods due to the influence of different types of dormancy mechanisms. Of these, enforced dormancy plays a most important role in maintaining the viability of buried seeds, especially with increased burial depth. 'Pawera' red clover seeds show a distinct periodicity of germination at different times of the year. This is an effective genetically controlled and environmentally modified seed survival mechanism.Item Totara Valley micro-hydro development : a thesis presented in partial fulfillment of the requirements for the degree of Master of Applied Science in Renewable Energy Engineering, Massey University, Palmerston North, New Zealand(Massey University, 2008) Donnelly, David RonaldThis study focuses on the design, construction and operation of a distributed generation system based on micro-hydro technology. The project is sited in the Totara Valley, a small rural community approximately 70km from the Massey University, Turitea campus, Palmerston North. The Massey University Centre for Energy Research (MUCER) has a long history of renewable energy research within the Totara Valley community. This project complements these existing schemes and provides a foundation for future research into distributed generation technologies. The project encompasses the following objectives: - to gain practical experience in the design, engineering and implementation of a distributed generation system in rural New Zealand; - to evaluate contemporary micro-hydro technology and compare the performance of this equipment in a theoretical and practical context; - to identify barriers that hinder the widespread adoption of micro-hydro systems in rural New Zealand; - to develop a spreadsheet based life cycle costing tool. The results from this study demonstrate that economic considerations are the fundamental aspect to be considered when assessing the long-term viability of these projects. The viability of micro-hydro projects are primarily determined by four factors: - the volume and head (height) of water available above the turbine site; - the length and therefore the cost of the pipeline required for transporting water to the turbine; - the legal and administrative costs involved in obtaining a resource consent to maintain access to the water resources; - the prices received and paid for electricity. Considerable charges were payable to the local authority to secure and maintain the right to harness the water resources at this site. This cost contributed considerable risk to the project and creates a significant barrier to establishing similar systems at other sites. The reduction of resource consent charges to levels that fairly reflect the negligible environmental impacts of these projects would encourage the adoption of this technology and deliver benefits to rural New Zealand communities.