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Item A study of vegetative and reproductive development in Caucasian clover (Trifolium ambiguum, M. Bieb.) cv. Monaro : 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, 1993) Efendi, FahamA four year established stand of Caucasian clover (Trifolium ambiguum,M.Bieb) cv. Monaro grown on Fine Sandy Loam with moderate fertility was studied to assess the vegetative and reproductive development and the effect of defoliation on seed yield and yield components from September 1991 to June 1992. As in many other traditional herbage legumes, an indeterminate growth habit and a protracted flowering period can be a factor limiting seed production in this clover. From the examination of the vegetative growth and flowering behaviour, it was found that the protracted flowering pattern in this clover is mainly caused by continuous production of reproductive shoots from the crowns rather than continuing inflorescence emergence in one stem as results indicated that inflorescences produced were mainly associated with the number of reproductive shoots available at the time of inflorescence emergence. Reproductive growth commenced at the beginning of October when most visible . Inflorescence buds were formed and subsequent flowering occurred about 8 weeks later. This reproductive growth was found to be the most concentrated on reproductive shoots/stems formed in November to December 1991. These reproductive shoots contributed the majority (70%) of proportion to total inflorescences. Inter-row cultivation decreased the number of reproductive shoots produced as well as decreasing the number of inflorescences at harvest. Inflorescences originating from main crowns produced a higher number of floret buds and seeds per inflorescence than those originating from secondary crowns as the main crowns have their own strong taproot system and are more mature. Throughout the flowering season, T. ambiguum consistently abort about 10 % flower buds before the flowers open. On average of 60% of the open florets developed into live pods at maturity, but only one from two ovules in an ovary usually developed into seeds. On average of about 72% of pods had one seed, 11% of pods with two seeds and 16% were without seed. Both in early and middle flowers, seed development studies revealed that maximum yield of high quality seed was obtained only when seeds attained their maximum dry weight at 30 days after pollination, at the time when seed moisture content had fallen to 30 to 40%. At this time the pods were yellowish brown in colour. To ensure the production of good quality seed with high yield in T. ambiguum it is necessary, therefore to wait crop until at least 34 days after pollination for harvesting the seeds. Seeds harvested early at day 14 to 22 did not retain their viability suggesting that these seeds was still immature and could not withstand desiccation. It was found that pod shattering begun at about 8 days after maximum dry weight (mass maturity) was reached. Heavy rainfall and strong dry wind was found to enhance the rate of shattering. Hardseededness was observed firstly in freshly harvested seeds when seed moisture contents were close to 20%. The levels of hardseededness was higher after drying. Inflorescences set later in the season produced more hard seeds due to higher temperatures and increased humidity during maturation stage. The results of this experiment have confirmed the high seeding potential of T. ambiguum (cv. Monaro) and this should facilitate the production of adequate seed supplies of this cultivars. The average seed yield potential, potential harvestable seed yield and actual seed yield was 893 kg/ha, 707 kg/ha and 427 kg/ha respectively. This might be attributed to the facts that the crop examined in this study was a four year established sward which was mature enough to produced a high yield. Another study was done involving late defoliation treatments designed to investigate their possible effects on plant growth and seed production. Cutting the plant to the ground level showed an obvious harmful effects on seed yield in T. ambiguum. The results show that October and November cutting resulted a 67 and 72% decrease in actual seed yield compared to uncut control. This results support Steiner's view (in press) that the plant morphology of T. ambiguum limits its ability to recover from defoliation.Item Phenotypic evaluation of Trifolium repens x Trifolium uniflorum F₁ interspecific hybrids as predictors of BC₁ hybrid progeny : a thesis presented in partial fulfilment of the requirements for the degree of Master of Science in Plant Breeding at Massey University, Palmerston North, New Zealand(Massey University, 2017) Ebbett, Michelle AnneInterspecific hybrids between white clover (Trifolium repens) and its close relatives are being created to address the lack of variation within white clover for traits relating to persistence and drought tolerance. This study addresses two concepts related to developing hybrid breeding strategies using Trifolium repens x Trifolium uniflorum hybrids. A first sandframe experiment investigated whether some of the first generation hybrid plants (F1) with common parents were better than others as future parents. A second experiment assessed whether the performance of the first back cross (BC1) progenies could be predicted from the parental F1 phenotypes. The foliage, fertility, roots and dry weight production of four families of F1 hybrids were evaluated following a period of growth in sand. From each family, the F1 hybrids with the highest and lowest dry weight production were selected and back crossed to two contrasting white clover cultivars. The resulting BC1 hybrid phenotypes were evaluated to ascertain whether any F1 hybrids were markedly better as future parents in hybrid breeding programmes, and whether the F1 phenotype could be used to predict that of the BC1 progeny. Differences in expression of more than half of the traits evaluated were found both between F1 families, and among genotypes within F1 families. Evaluation of the subsequent BC1 generation identified large amounts of variation in expression of most traits both within and among hybrid families. However correlations between trait expression of the F1 parent and the corresponding BC1 progeny were weak to non-existent for most traits evaluated. The absence of correlations indicated that the performance of an F1 hybrid genotype is not able to be used as a predictor of the BC1 progeny phenotypes, and that selection out of the F1 generation is futile in the formation of interspecific hybrid breeding populations.Item Comparative cytogenetics in the genus Trifolium section Trifolium (clover) : a thesis presented in partial fulfilment of the requirements for the degree of Master of Science in Plant Biology at Massey University(Massey University, 1999) Bucknell, Tatyana ThelmaFive species in genus Trifolium section Trifolium were investigated cytologically. The species investigated were T. pratense, T. hirtum, T. incarnatum, T. alexandrinum and T. striatum. A new modified air-dried technique was used to prepare the chromosomes in order to overcome difficulties related to small chromosome size and also to produce metaphases suitable for fluorescence in situ hybridisation. Chromosome numbers were confirmed for all species. T. hirtum was morphometrically analysed using the confocal microscope and Silicon Graphics image analysis software, C-banded, Q-banded and subjected to fluorescence in situ hybridisation (FISH). The FISH revealed a unique distribution pattern for 18s and 5s rDNA with the 5s and 18s signals present on the satellited chromosome pair only. For 5s rDNA, hybridisation sites were observed in three areas of the satellited chromosome, two of those sites were on either side of the 18s signal. Idiograms showing chromosome lengths and the position of C-bands were also produced. T. pratense was Q-banded and its chromosome number confirmed as 2n=2x=14. The chromosome number of T. incarnatum was confirmed as 2n=2x=14 rather than 2n=2x=16 as reported in some literature; the species was also C- banded. The chromosome number of T. alexandrinum was confirmed as 2n=2x=16. The chromosome number of T. striatum was confirmed as 2n=2x=14. This is the first time any species in the genus Trifolium section Trifolium have been successfully C-banded, Q-banded, and subjected to fluorescence in situ hybridisation. The information gained will go some way towards illuminating the evolutionary relationships between species in the section Trifolium and also in the genus Trifolium, whilst also giving support to breeding programs in place and those planned for the future.Item Dynamical systems models for growth of ryegrass and clover : a thesis presented in partial fulfilment of the requirements for the degree of Master of Science in Mathematics at Massey University(Massey University, 1998) Flux, TraceyThis thesis presents models formulated to describe ryegrass and clover growth independently, with the long-term goal of constructing a unified ryegrass/clover model. The purpose of this unified model will be to address the questions of co-existence of ryegrass and clover when grown together, and persistence of ryegrass in these mixed pastures. An overview of the problem and background of the biology is provided. This may be particularly useful for the reader with no prior knowledge of ryegrass or clover biology. A physiologically-based model for ryegrass growth is investigated. This model is a modification of that proposed by Johnson and Thornley [14] who only consider the vegetative growth phase. The modified model accounts for the reproductive growth phase. Some numerical results, with and without reproduction, are presented. These results show that increased growth occurs when reproduction is included. A model for ryegrass growth based on tiller numbers is then investigated. This model has far fewer state variables than the above-mentioned physiologically-based model, although only vegetative growth is considered. The differential-delay equations which result from the mathematical formulation of this model are presented. Mathematical analysis of these equations reveals two steady states: a zero steady state and a finite steady state. A threshold condition that determines which of these two steady states is eventually reached is given. The effects of harvesting the growth are also studied using numerical simulation. Two models for clover growth, both of which are structurally similar to the second ryegrass model, are described. However the first clover model does not have any inbuilt delay mechanisms. Mathematical analysis of these models also shows the existence of two steady states: a zero steady state and a finite steady state. Again, a threshold condition determining which of these is eventually reached is given. There is little difference between the results from the two clover models, even when the numerical simulations from harvesting are considered. Finally, a summary is given of the models studied and an indication of possible extensions to these models. A suggestion as to how a unified ryegrass/clover model might be formulated is also given.Item The pelleting of clovers and fertiliser : the effects of the localized placement of fertiliser at seeding (pelleting) on germination, morphology and herbage yield of Trifolium species : a thesis presented in partial fulfilment of the requirements for the degree of Master of Agricultural Science to the University of New Zealand [Massey Agricultural College](Massey Agricultural College, 1951) Smith, C. AThe pelleting of clover seed and fertiliser may be valuable as a method of introducing the essential clovers into the unploughable hill country. The hill land of New Zealand is agriculturally important because of the large area involved, the animals and animal products produced and its value as a souce of direct and indirect employment. The hill country indirectly influences the valuable lowlands. There are two aspects: firstly, the supply of store stock for fattening and breeding (which results in a continuous transfer of minerals as animal skeletons); and secondly the importance of the hill catchment areas in the prevention of flood discharges, and the silting of rivrs, flats and resevoirs lower down.Item Analysis of seed production traits in interspecific hybrids between Trifolium repens (white clover) and Trifolium uniflorum : a thesis submitted in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Plant Breeding and Genetics at Massey University, Palmerston North, New Zealand(Massey University, 2013) Naeem, MuhammadTrifolium repens L. (white clover) is an important component of New Zealand’s pastoral and herbage seed industries. It has delicate shallow roots vulnerable to drought and pest attack. T. uniflorum is a wild species, adapted to dry environments, with deep woody roots but poor vegetative growth and only 1-3 florets per head. Hybridization was done to incorporate the drought tolerance and root characteristics of T. uniflorum into white clover. The primary hybrids (F1 and BC1F1) showed poor seed production. The project aimed to analyse this problem and improve seed production by further hybridization and selection. The hybrids expressed high variation for almost all seed production traits. Heads per plant, florets per head and seeds per floret were important determinants with moderate to high heritabilities. The derived traits seeds per head, florets per plant and seeds per plant expressed low-moderate to moderate heritabilities. Flowering pattern showed high heritability. No negative correlations between seed production and root traits were found. Whereas nodes per stolon favoured head production, stolon production had a negative effect on nodes per stolon. No negative associations between head production, persistence and foliage production of the hybrids were observed. No cytoplasmic influences were evident. The hybrids showed, higher self fertility and a wider gap between potential and actual seed yield than white clover. The BC1F1 generation produced low numbers of heads per plant and seeds per floret. Intercrossing coupled with recurrent selection improved variation, fertility and realization of potential seed yield. The second backcrossed and intercrossed generations had high seeds per floret and plant. Backcrossing of selected hybrids effectively recovered the white clover phenotype and created new variation. The BC2F1 and BC3F1 generations expressed the better head production ability of T. uniflorum combined with the bigger head size of white clover. Seed production capability of the hybrids was successfully restored. More genetic variation was created in the hybrids for future breeding and selection endeavours.Item Purification and characterisation of cell wall acid phosphatases of roots of white clover (Trifolium repens L.) : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Plant Biology at Massey University, Palmerston North, New Zealand(Massey University, 1999) Zhang, Celia; Zhang, CeliaPlants of white clover (Trifolium repens L., cultivar Huia, genotype PgH2) were either grown in half-strength Hoaglands solution (P-containing media) or subjected to phosphate starvation by omitting the sole source phosphate (KH2PO4) from Hoaglands solution media for a period of five weeks. The phosphate content of the first fully expanded leaf was determined in plants from both treatments. After 2 weeks, the P content in leaves from plants grown in P-deprived media was significantly lower (p < 0.001) than the P-supplied plants, and continued to decrease over the 5-week time course. Ionically bound acid phosphatases were extracted with 1 M NaCl from the cell walls of roots. In roots of plants maintained in P-deprived media, acid phosphatase activity increased over the 5-week time course, while the activity in roots of plants grown in P-containing media did not change. After four weeks in P-deprived media, the cell wall ionically-bound acid phosphatase fraction was subjected to hydrophobic column chromatography and two distinct acid phosphatases (designated Apase I and Apase II) identified. There is a temporal difference in induction of Apase I and Apase II. After one week of P-deprivation, the activity of Apase II reached its maximum and did not increase further in following weeks. The activity of Apase I was only half that of Apase II after one week of P-deprivation, but increased continually to be significantly higher than the activity of Apase II by the end of week 4. Apase I and II were further purified using gel filtration column chromatography, and each enzyme subsequently separated further into two isoforms by ion-exchange chromatography. Both isoforms of Apase I (Ia and Ib) exist as active monomers of 52 kD as determined by SDS-PAGE and by gel filtration. For Apase II, both isoforms (IIa and IIb) also exist as active monomers of 112 kD as determined by SDS-PAGE and 92 kD by gel filtration. Both Ia and Ib are glycosylated as determined by recognition by a Galanthus nivalis (GNA) lectin (which recognises terminal mannose or oligomannose N-linked glycan chains) or by a monoclonal antibody YZ1/2.23 (which recognises xylose/fucose-containing complex-type glycan chains). Apase Ia was recognised by both sugar probes, while Apase Ib was recognised by YZ1/2.23 only. Apase IIa was not recognized by either of sugar probes, while Apase IIb is a glycoprotein as determined by recognition by YZ1/2.23. Using ρNPP as substrate, the pH optima for Apase Ia, Ib, IIa and IIb are 5.8, 6.2, 5.8 and 6.8, respectively. Isoelectric focusing determined that Apase Ia split into two bands with pI values of 7.0 and 7.3, Apase Ib showed a major band with a pI of 6.7, Apase IIa showed a single band with a pI of 4.4 and Apase IIb split into two closely located bands with pI values of 5.2 and 5.3. The activity of all four isoforms was severely inhibited by Cu2+, Zn2+ and molybdate. Fe3+ is also an inhibitor but not as potent as the other three metal ions. Co2+ and Al3+ displayed greater inhibition of Apase I when compared with Apase II. Tartrate and EDTA had no effect on the activity of all four isoforms, but inorganic phosphate is a strong inhibitor of all the four isoforms. Each of the four isoforms showed a broad range of substrate specificity, with ATP and PPi the preferred substrates, and PEP and 3-PGA the least preferred substrates. All four isoforms showed no hydrolysis activity toward phytic acid. A short sequence containing 5 amino acid residues was obtained from Apase Ib, but no significant sequence identity with any existing protein sequence was found.Item Seed production in Caucasian clover (Trifolium ambiguum Bieb.) cv. Monaro : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in the Institute of Natural Resources of Massey University, Palmerston North, New Zealand(Massey University, 1998) Fu, Shimin; Fu, ShiminA number of factors which may affect seed production in Caucasian clover (Trifolium ambiguum Bieb.) cv. Monaro were investigated viz. root system development and its relationship with seed yield; morphological and reproductive characteristics of different genotypes from within the cultivar; the effects of plant density on seed yield; and, the effects of insect pests on seed yield and quality. Caucasian clover is a rhizomatous legume pasture plant with a large root system. A sand bed was used to investigate root system development and the relationship between the root system and seed yield. During vegetative growth (September to November) root dry matter (DM) accumulated more rapidly than shoot DM, and the root to Shoot ratio was 2.45 by mid November. However as reproductive growth accelerated the rate of root DM accumulation decreased and by early February the root to shoot ratio was 0.65. Plants developed primary, secondary and tertiary crowns in this first growing season, with both primary and secondary crowns producing reproductive shoots. The protracted flowering period (four months) was a result of an initial production of reproductive shoots from primary crowns, and an extended production of reproductive shoots from secondary crowns when primary crown shoot production had ceased. There were therefore two flowering peaks. A single primary crown produced an average seed yield of 3.8 g compared with 0.81 g seed from an average secondary crown. However as there was only one primary crown but 26 secondary crowns per plant, the total seed yield from secondary crowns reached 21.1 g per plant. Root DM was highly correlated (R2 = 0.80-0.97) with the number of leaves, reproductive shoots and inflorescences, as well as the number of secondary crowns. Seed yield per plant was almost entirely dominated by the number and size of the secondary crowns, which in turn depended on the size of the root system prior to reproductive development. The seed production potential of three genotypes selected from within cv. Monaro was investigated. The genotypes differed significantly in their morphological and reproductive characteristics, including the number of reproductive stems and inflorescences produced. Genotypes 2 and 12 had seed yields of 3.65 g and 2.99 g per plant respectively, which genotype 9 had a seed yield of only 0.18 g per plant, primarily because it produced very few inflorescences. Poor inflorescence production by some genotypes within a cultivar will limit seed yield and may alter the genotypic composition of the cultivar as seed multiplication progresses. A radial trial was used to determine the optimal density for seed production of the cultivar. Plant density significantly affected leaf number, reproductive stems, inflorescences number and seed yield per plant in that plants at the highest density (38.2 m-2) produced about 7 times fewer reproductive stems and over 15 times fewer inflorescences per plant compared with those in the lowest density (3.1 m-2). Inflorescence number increased as plant density decreased (R2 = 0.82-0.89). The lowest density plants had the greatest reproductive growth per plant but were not capable of creating the highest reproductive production per unit area. Cultivar Monaro showed a parabolic relationship for reproductive production per unit area with plant density, both for inflorescence number and seed yield m-2. Plants grown at the density of 10.8 plants m-2 produced the highest inflorescence number and seed yield per unit area. The number of inflorescences per plant was the most important seed yield component determining final seed yield in cv. Monaro (R2 = 0.95). Plant density affected seed yield only through reducing inflorescence number; it had no effect on thousand seed weight, or germination and hard seed percentage. It is probable that plant density affects reproductive development through its effects on root system development in Caucasian clover. A semi-radial trial was also used to examine the effects of plant density on seed production of twelve genotypes from within cv. Monaro. These genotypes demonstrated significant differences in reproductive capability. Genotypes 1, 2, 4 and 12 represented a high or normal reproductive capability group compared with others and these genotypes produced inflorescences across all five densities. Genotypes 3, 5, 8, 9, 13 represented another group which either failed to produce or produced only a small number of inflorescences even at the lowest density. Genotypes 6, 7 and 10 were intermediate. Seed yield per plant at the 10.8 plants m-2 density ranged from 0 g for genotypes 5, 8, 9 and 13 to 0.89 g for genotype 1. Reproductive response to plant density did not differ from that when seeds of the cultivar were sown in the full radial trial. Insect pests, particularly thrips (Thripidae) may reduce seed yield and quality. The insecticide taufluvalinate (Mavrik) was applied at 150 ml ha-1 either once (just prior to peak flowering) or every 14 days until harvest, beginning at first inflorescence appearance. Both adults and larvae of onion thrips (Thrips tabaci) and red clover thrips (Haplothrips niger) were detected in inflorescences during peak flowering and seed development. The multiple insecticide applications significantly increased seed number per inflorescence and thousand seed weight, therefore increasing seed yield. However the single application had no effect on seed yield or quality.Item Determination of digestion parameters to develop and evaluate forage mixtures for pasture-fed ruminants : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Animal Science at Massey University, Palmerston North, New Zealand(Massey University, 2004) Burke, Jennifer LeighannAnimal production can be improved by lessening the dependence on ryegrass-based pastures as the sole source of nutrients for production. Ryegrass varies in quality and availability and supplementation with appropriate forages will maintain or improve production. This thesis defines the nutritive characteristics of a range of forages, including temperate and tropical grasses, legumes with and without condensed tannins, herbs and silages, in terms of chemical composition, products of degradation and rates of digestion using in sacco and in vitro methods. The forages assessed varied in crude protein concentration (CP; 7.6 - 29.9 % of dry matter; DM) and neutral detergent fibre (NDF; 22.4 - 57.8% DM), with commensurate net appearance of plant N as ammonia (0 to 49%) and in sacco DM, CP and NDF degradation rates (%/h) from 3 - 26, 3 - 19 and 4 - 28, respectively. The Cornell Net Carbohydrate Protein System (CNCPS) was used to evaluate the ability of forages to meet the energy and protein requirements of dairy cows. Data suggested sulla (Hedysarum coronarium), lucerne (Medicago sativa), red clover (Trifolium pratense) and white clover (Trifolium repens) as potential forages for feeding with medium to low quality pasture. Lambs were fed pasture, white clover, lucerne and sulla alone or in mixtures and production, rumen digestion parameters and estimates of protein synthesis were measured. Lambs fed white clover, sulla, lucerne:sulla and white clover:sulla had the highest daily intakes (1.47 - 1.54 kg DM) and liveweight gains (281 - 308 g) compared to lambs fed pasture (1.10 kg DM; 116 g). Sulla had potential for feeding with pasture and lucerne, but energy limited production. Protein synthesis between lambs fed lucerne, sulla and lucerne:sulla were similar (162 - 180 g/day) and greater than pasture (93 g/day). In a trial with dairy cows fed pasture (P), supplementation with maize silage (M) or sulla (S) did affect in sacco degradation and the maize silage lowered in sacco DM degradation rates (P, 7; M, 4; S, 16; P:M; 5; P:S, 11 and P:M:S, 6 %/h). The work presented provides a foundation for formulating mixed forage rations to meet cow nutrient requirements and improve productivity in ryegrass-based pasture systems. Animal trials demonstrated synergistic effects of dietary components on both animal production and rumen microbial function.