An in vitro system of generating protoplasts from their callus cultures was established. The friable callus was more productive in terms of producing protoplasts than the green compact callus. The concentration of the various cell wall degrading enzymes had an effect on the viability of the protoplasts in the medium. The protoplast system developed from the experiments was stable and could be used for the transformation experiments of Albizia lebek and for other plant improvement practices.

<p dir="ltr">Routine testing of nutrient concentrations via plant tissue is an important component of in-season fertilizer management in maize (<i>Zea</i> <i>mays </i>L.) cropping systems. Accuracy of results are critical for nitrogen (N), phosphorous (P), potassium (K), and sulfur (S) management, yet there is little scientific guidance on which leaf to sample during mid- to late-vegetative growth stages. Additionally, the whole-plant status of each macro-nutrient may be best represented by a different leaf position due to mobility differences among nutrients. Mobility of each nutrient and allocation within the plant may also be influenced by environmental factors, management strategies, and genotype selection. Field experiments were conducted in West Lafayette and Windfall, Indiana in 2021 and 2022. The objectives were to (1) evaluate N, P, K, and S concentrations of specific leaf positions and whole plants in response to N fertilizer rate (NR), planting density (PD), and genotype (G) treatments at multiple growth stages, and (2) determine the ability of various leaf positions to predict whole-plant concentrations of N, P, K, and S across multiple NR, PD, and G environments. The West Lafayette study compared three NR treatments applied as urea-ammonium nitrate (UAN, 28-0-0) at the V5 growth stage and included (1) Control, no N applied, (2) 151 kg N ha^-1, and (3) 241 kg N ha^-1. The Windfall study compared two side-dress UAN rates of (1) Control, no N applied, and (2) 224 kg N ha^-1 at two planting densities (sub-plot) of 49,400 plants ha^-1and 89,000 plants ha^-1 with 4 Pioneer^® genotypes (sub-sub-plot) including two historical double-cross hybrids and two modern single-crosses. Tissue sampling included the top-collared leaf and whole-plant at V8, the 8^th leaf, top-collared leaf, and whole-plant at V12, and the 8^th leaf, 12^th leaf, ear-leaf, top-collared leaf and whole-plant at R1. Tissue N concentrations were consistently responsive to NR and PD treatments at all stages, but bottom leaves better reflected NR changes. As a mobile nutrient, N concentrations were highest in the uppermost leaf positions by R1 (ear-leaf and top-leaf), yet regressions between individual leaf and whole-plant N% were highest in the lower leaf positions (8^th and 12^th leaf positions). This suggested that the more likely a specific leaf was to exhibit nutrient deficiency symptoms, the better it would be at predicting whole-plant concentrations of that nutrient. Regressions between individual-leaf and whole-plant N% (modern genotypes only) increased from V8 to R1 and regressions were best with the 12^th leaf position at both V12 and R1. Tissue S concentration responses to NR increased at later growth stages, and top-leaf S was a stronger reflection of whole-plant S than the 8^th leaf. Despite S concentration differences among leaf positions at R1, the strength of regressions between each leaf position and whole-plant S were similar. There was no optimal leaf position to represent whole-plant S. While leaf N and S concentrations were above whole-plant concentrations, leaf P and K concentrations exhibited the opposite dynamic. There was little leaf P response to experimental treatment factors, and although regressions for leaf P versus whole-plant P concentrations were far weaker than for N, S or K, the 8^th leaf position was preferred at V12 and R1 (R² of just 0.27 and 0.36, respectively). Potassium concentration response to NR was weak. However, leaf K% and whole-plant K% were highly related via regression, irrespective of NR, at all three stages. Prediction of whole-plant K was strongest with the 8^th leaf at V12 and the 12^th leaf at R1. In summary, optimum leaf sampling position was shown to vary with individual macronutrients and growth stages in maize. Although more research is essential, these preliminary results indicate that traditional sampling methods involving selection of the top fully-expanded leaf from V8 to silking, and the ear-leaf during post-silking stages, may not be the most reliable indicators of whole-plant nutrient status.</p>

1 ABSTRACT Kateřina Muráriková Influencing of production of plant tissue culture of Trifolium pratense L. I The aim of this thesis was to check the influence of cinnamic acid, as a precursor of the phenylpropanoids biosynthesis, on the flavonoids production of Trifolium pratense L. suspension culture, to compare two varieties of this plant, the DO-8 one and the Tempus one, in terms of the effect of this precursor, and to help achieve the successful increase of the production of secondary metabolites by the Trifolium pratense L. explant cultures. Concerning the DO-8 variety, the changes of the isoflavonoids production as a result of the cinnamic acid influence have been also tested. The suspension cultures were being cultivated on the Gamborg's nutrient medium with the addition of 2 mg.l-1 2,4-dichlorphenoxyacetic acid and 2 mg.l-1 6-benzylaminopurine. The cultivation was being realised on a slow moving roller at temperature of 25 řC and in the period of 16 hours of light and 8 hours of dark. The cinnamic acid was added in the four concentrations and its influence was observed after 6, 24, 48 and 168 hours. The flavonoids determination was being applied on the check samples and the samples with the addition of cinnamic acid by the spectrophotometric method in agreement with the Český lékopis 2009 and the...

Lucie Částková Influencing of production of plant tissue culture of Trifolium pratense L. II The aim of this thesis was to observe the effect of the abiotic elicitor vanadyl sulfate on the production of flavonoids in the suspension culture of Trifolium pratense L., variety DO-8 and variety Sprint. The effects on the production of isoflavonoids caused by the elicitor have been also studied. The cultures were cultivated at the temperature of 25 žC, 16 hour light/8 hour dark period, in the Gamborg's nutriet medium with the addition of 2 mg.l-1 of 2,4- dichlorophenoxyacetic acid and 2 mg.l-1 of 6-benzylaminopurine. Vanadyl sulfate was added in four concentrations and its influence was observed after 6, 24, 48 and 168 hours. The quantity of flavonoids was determined spectrophotometrically according to the Pharmacopoeia Bohemica 2009. The quantity of isoflavonoids was determined using HPLC. The maximal content of flavonoids, 0,459 %, was measured in the suspension culture of Trifolium pratense L., variety DO-8, taken after 48 hours of action of elicitor vanadyl sulfate, which concentration was 1 µmol.l-1 . The statistically significant increase in production was 106 % compared to the control. The production of flavonoids in variety Sprint was most influenced by the action of vanadyl sulfate, which...

Soyabean meal (SBM), the major protein source in feeds in sub-Saharan Africa, is in short supply. The shortage is a major constraint to intensified animal production to meet increased demand hence the dire need to search for alternatives. Kigelia africana, Mumisops zeyheri, Terminalia sericea and Ximenia caffra are indigenous fruit bearing trees (IFBTs) whose seeds’ potential as alternative protein sources in feeds were evaluated. The evaluation consisted of an initial physico-chemical characterization of the seeds followed by determining in vitro the safety of seed oils on cell lines. Based on the physico-chemical and in vitro evaluation, the most suitable seed was selected, defatted and its meal used as a dietary substitute to SBM in the in vivo trials using adult and weanling male Sprague Dawley rats. The T. sericea seed yield was not viable. Chemically K. africana and X. caffra seed demonstrated potential as protein sources in feeds. M. zeyheri seed demonstrated potential as an energy source. The IFBTs seeds oil yield surpassed that of some traditional oilseed crops. Oleic and linoleic acid were the major fatty acids contained in the oils. In vitro, K. africana, M. zeyheri and X. caffra seed oils suppressed Caco-2 and HEK-293 cell proliferation without causing cell death. X. caffra seed, deemed the most suitable, was defatted and its seed meal used in the in vivo trials. In mature rats, dietary substitution of SBM with the defatted X. caffra seed meal did not affect (P > 0.05) dry matter intake, apparent digestibility of nutrients and nitrogen absorption and retention. In weanling rats, the defatted X. caffra seed meal had no effect on termination (body mass at the end of the feeding trial) and empty carcass mass and linear growth of the rats. Metabolic substrate storage, fasting blood glucose concentration and the general health profile of the growing rats were not altered by dietary X. caffra seed meal. The defatted X. caffra seed meal increased the mass of the stomach and small intestine (P = 0.0071; P = 0.0001) of rats on the test diet where a 100% dietary crude protein (CP) from SBM was substituted by CP from the defatted X. caffra seed meal. Defatted X. caffra seed meal could substitute SBM in rat and possibly monogastrics feeds without compromising digestibility, nitrogen balance, growth and general health.

No description available.

Throughout the years lime-induced chlorosis has contributed to untold economic losses. Although this disease has challenged the technical ingenuity of outstanding plant and soil scientists, the exact cause has never been determined; consequently, no preventative measures or permanent cures can, as yet, be recommended. This physiological malady, unchecked, continues its rampage in regions where the disease is prevalent.

For this research, the abnormality of tissue cultured plantlets,vitrification, was examined in Gypsophila paniculata.Measurement of the relative water content and water saturation deficit of plantlets in culture revealed that vitrified plantlets contain relatively more water and less air spaces than non-vitrified plantlets.The effect of relative humidity on vitrification and growth was investigated using a variety of methods.From the results found, it was determined the defining characteristic of vitrified plantlets is water filled intercellular spaces. It was also determined that the primary cause of vitrification is high relative humidity resulting in a lack of transpiration in vitro but that other factors such as unbalanced mineral nutrition or high medium cytokinin can exacerbate vitrification.Further research in tissue culture may investigate the influence of relative humidity on plant growth and morphology, the mechanism by which plants exclude water from their intercellular spaces and refine in vitro tissue mineral analysis as a means by which critical mineral concentrations can be determined. / Doctor of Philosophy (PhD)

Thesis (M. Phil.)--University of Hong Kong, 1981.

published_or_final_version / Botany / Master / Master of Philosophy