scholarly journals An Improved Protocol for Agrobacterium-Mediated Transformation in Subterranean Clover (Trifolium subterraneum L.)

2021 ◽  
Vol 22 (8) ◽  
pp. 4181
Author(s):  
Fernando Perez Rojo ◽  
Sumedha Seth ◽  
William Erskine ◽  
Parwinder Kaur
Keyword(s):  
Agrobacterium Tumefaciens ◽  
Nutritive Value ◽  
Transformation Efficiency ◽  
Incubation Temperature ◽  
Agronomic Traits ◽  
Genetic Manipulation ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Factors Affecting

Subterranean clover (Trifolium subterraneum) is the most widely grown annual pasture legume in southern Australia. With the advent of advanced sequencing and genome editing technologies, a simple and efficient gene transfer protocol mediated by Agrobacterium tumefaciens was developed to overcome the hurdle of genetic manipulation in subterranean clover. In vitro tissue culture and Agrobacterium transformation play a central role in testing the link between specific genes and agronomic traits. In this paper, we investigate a variety of factors affecting the transformation in subterranean clover to increase the transformation efficiency. In vitro culture was optimised by including cefotaxime during seed sterilisation and testing the best antibiotic concentration to select recombinant explants. The concentrations for the combination of antibiotics obtained were as follows: 40 mg L−1 hygromycin, 100 mg L−1 kanamycin and 200 mg L−1 cefotaxime. Additionally, 200 mg L−1 cefotaxime increased shoot regeneration by two-fold. Different plant hormone combinations were tested to analyse the best rooting media. Roots were obtained in a medium supplemented with 1.2 µM IAA. Plasmid pH35 containing a hygromycin-resistant gene and GUS gene was inoculated into the explants with Agrobacterium tumefaciens strain AGL0 for transformation. Overall, the transformation efficiency was improved from the 1% previously reported to 5.2%, tested at explant level with Cefotaxime showing a positive effect on shooting regeneration. Other variables in addition to antibiotic and hormone combinations such as bacterial OD, time of infection and incubation temperature may be further tested to enhance the transformation even more. This improved transformation study presents an opportunity to increase the feeding value, persistence, and nutritive value of the key Australian pasture.

Plant factors influencing the nutritive value of some temperate annual pasture species

1973 ◽  
Vol 13 (63) ◽  
pp. 404 ◽  
Author(s):  
JG McIvor ◽  
DF Smith
Keyword(s):  
Nutritive Value ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Growth Cycle ◽  
Matter Content ◽  
In Vitro Digestibility ◽  
Dry Matter Content ◽  
Hordeum Leporinum ◽  
Brome Grass

Changes in herbage production, dry matter content, nitrogen content and in vitro digestibility of two sown species-subterranean clover (Trifolium subterraneum) and annual ryegrass (Lolium rigidum) - and five common volunteer species-capeweed (Arctotheca calendula), musky crowfoot (Erodium moschatum), barley grass (Hordeum leporinum), ripgut brome grass (Bromus rigidus) and soft brome grass (Bromus mollis)-were measured throughout their growth cycle. The volunteer species compared favourably with the sown species for these measurements and should be capable of providing nutritious grazing for animals.

Anti-methanogenic advantage of biserrula (Biserrula pelecinus) over subterranean clover (Trifolium subterraneum) from in vitro fermentation is maintained across growth stages and cutting treatments

2019 ◽  
Vol 70 (3) ◽  
pp. 263
Author(s):  
Bidhyut Kumar Banik ◽  
Zoey Durmic ◽  
William Erskine ◽  
Clinton Revell
Keyword(s):  
Growth Stage ◽  
Nutritive Value ◽  
Subterranean Clover ◽  
In Vitro Study ◽  
Trifolium Subterraneum ◽  
Reproductive Stage ◽  
Growth Stages ◽  
Plant Collection ◽  
Grazing Systems

The annual forage legume biserrula (Biserrula pelecinus L.) offers a promising opportunity as a low-methanogenic, bioactive pasture for southern Australian grazing systems where subterranean clover (Trifolium subterraneum L.) is the dominant annual pasture legume. This in vitro study to assess methanogenic potential examined how growth stage and cutting of biserrula affect biomass, nutritive value and fermentative parameters including methanogenic potential compared with subterranean clover. Both species were grown in a glasshouse, where three growth-stage treatments comprised plant collection at vegetative, reproductive or maturity growth stages. Three cutting (simulated grazing) treatments included cutting at the vegetative or reproductive stage and an uncut control, with herbage collection at maturity. Methane production in biserrula was unaffected by the stage of growth. Other nutritive value and fermentative parameters varied significantly with growth stage, the highest fibre content and lowest crude protein (CP) being found at maturity. Regrowth from herbage cut at the reproductive stage had higher CP and lower biomass than other cut treatments. In biserrula, this regrowth also showed the highest fermentability of the three cutting treatments including elevated methane yield. Notwithstanding these treatment effects on fermentability, biserrula maintained its strong anti-methanogenic advantage over subterranean clover across all treatments, confirming its potential as an anti-methanogenic bioactive pasture.

The in vitro inhibition of Phytophthora clandestina by some rhizobia and the possible role of Rhizobium trifolii in biological control of Phytophthora root rot of subterranean clover

1999 ◽  
Vol 50 (8) ◽  
pp. 1469 ◽  
Author(s):  
S. Simpfendorfer ◽  
T. J. Harden ◽  
G. M. Murray
Keyword(s):  
Biological Control ◽  
Root Rot ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Root Disease ◽  
Rhizobium Trifolii ◽  
Biological Control Agents ◽  
Control Activity ◽  
Phytophthora Root Rot

The interaction between 29 isolates of Rhizobium and the in vitro growth of 3 strains of Phytophthora clandestina was investigated to determine the potential of these bacteria as biological control agents against root rot of subterranean clover (Trifolium subterraneum L.). The biological control activity of Rhizobium on the severity of root disease in seedlings was also investigated under glasshouse conditions. Thirteen of the 29 Rhizobium isolates caused significant reductions in the hyphal growth of the 3 P. clandestina isolates examined. Inoculation of seedlings with Rhizobium trifolii reduced the severity of root disease by 14–58% with corresponding increases in dry matter production of 20–73%. These results indicate that Rhizobium species have potential as biological control agents against the root rot of T. subterraneum seedlings caused by P. clandestina.

Flower initiation in pasture legumes. I. Factors affecting flower initiation in Trifolium subterraneum L.

1955 ◽  
Vol 6 (2) ◽  
pp. 211 ◽  
Author(s):  
Y Aitken
Keyword(s):  
Low Temperature ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Cold Period ◽  
Effect Of Temperature ◽  
Flower Initiation ◽  
Temperature Level ◽  
Factors Affecting ◽  
Pasture Legumes ◽  
Precise Knowledge

The value of the annual legume Trifolium subterraneum L. (subterranean clover) in Australian agriculture warrants more precise knowledge of factors affecting flowering and prolific seeding. The effect of temperature and photoperiod on flower initiation in early and later flowering varieties has been investigated in an effort to determine the geographical limits of the use of subterranean clover in Australia. At any time of sowing, the length of the growing season of a variety depends greatly on the variety's response to the temperature level and to the photoperiod of the first few weeks after germination. In all varieties of subterranean clover so far examined flower initiation is accelerated by a period of low temperature. In the later varieties, flower initiation is prevented by an insufficient period of low temperature. The length of the necessary cold period is shortened under longer photoperiod. Early varieties are early flowering because they do not require so long a cold period or so low a temperature as late varieties.

Seed yield and nutritive value of dry, mature subterranean clover (Trifolium subterraneum L.)

2001 ◽  
Vol 41 (2) ◽  
pp. 169 ◽  
Author(s):  
Y. J. Ru ◽  
J. A. Fortune
Keyword(s):  
Seed Yield ◽  
Dry Matter ◽  
Mineral Content ◽  
Nutritive Value ◽  
Subterranean Clover ◽  
Zinc Content ◽  
Trifolium Subterraneum ◽  
Crude Fibre ◽  
Dry Matter Digestibility ◽  
Wide Range

The nutritive value of 26 cultivars of dry, mature subterranean clover was evaluated at Shenton Park, Perth, Western Australia. The cultivars were divided into 3 maturity groups according to flowering time and each cultivar was sown in blocks comprising 4 replicates. The plots were grazed by sheep at 2-week intervals during the growing season. Dry mature plant material and soil were sampled in summer to examine the effect of grazing and cultivar on seed yield and nutritive value of feed residues. Cultivars heavily grazed in spring had a low herbage mass. There was no difference in seed yield and seed weight between heavily and lightly grazed cultivars. Dry matter digestibility and mineral content of dry residues was inconsistent for the 2 grazing treatments. The dry matter digestibility of dry, mature subterranean clover ranged from 40 to 56%, with a wide range of crude fibre, nitrogen and mineral content for the 26 cultivars. While most minerals in the dry residues were above the requirement for sheep, 7 cultivars had a zinc content less than the maintenance requirement for sheep. There was an imbalance for all cultivars in calcium: phosphorus with a range of 4–10: 1. Concurrent estimates on the yield and composition of seed indicated that seed can be resource of minerals for grazing animals in summer. Most cultivars had a seed yield over 100 g/m2 with that of 9 cultivars being over 130 g/m2. Seed was rich in nitrogen, sodium, phosphorus, potassium, magnesium, zinc and copper, and poor in sodium, calcium and manganese. However, there were no cultivars with an appropriate ratio of calcium and phosphorus. The imbalance in nitrogen and sulfur was a result of high nitrogen content with the ratio ranging from 19: 1 to 29: 1.

The growth of barley grass (Hordeum leporinum) in annual pasture. 3. Some factors affecting balance with subterranean clover (Trifolium subterraneum)

1968 ◽  
Vol 8 (35) ◽  
pp. 702 ◽  
Author(s):  
DF Smith
Keyword(s):  
Soil Nitrogen ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Moisture Stress ◽  
Nitrogen Addition ◽  
The Other ◽  
Early Start ◽  
Factors Affecting ◽  
Two Factors ◽  
Hordeum Leporinum

Mixed swards of barley grass (Hordeum leporinum) and subterranean clover (Trifolium subterraneum) of two densities were grown at two levels of nitrogen. Growth was started at two different times mid- April and mid-May-and at each time half the plots were subjected to moisture stress. The swards were harvested after nine weeks of growth. The survival of clover plants was reduced by an early start, moisture stress and nitrogen addition : much more so than barley grass. The root : shoot ratios of both species were calculated ; both showed some sensitivity to the time of break and moisture stress, and the grass was also affected by the other two factors. Total sward production and the ratios of clover to grass varied widely Grass daminance was favoured by moisture stress or a late break, and both of these factors tended to override the effect of higher soil nitrogen in determining clover-grass balance. Total sward production more dependent on density than any other factor, especially with the later start. Higher nitrogen was effective in boosting production only if the break was early and there was no moisture stress.

Seed production and persistence of Carnamah and other early strains of Trifolium subterraneum in the wheatbelt of Western Australia

1967 ◽  
Vol 7 (24) ◽  
pp. 25 ◽  
Author(s):  
GB Taylor ◽  
RC Rossiter
Keyword(s):  
Seed Production ◽  
Seed Yield ◽  
Western Australia ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Growing Season ◽  
Early Flowering ◽  
The Other ◽  
Factors Affecting ◽  
Seed Yields

Seed production and persistence of the Carnamah, Northam A, Dwalganup, and Geraldton strains of subterranean clover (Trifolium subterraneum L.) were examined in undefoliated swards in the wheatbelt of Western Australia. The early flowering characteristic of Carnamah was not always associated with higher seed yields. Only when there was a well-defined, early finish to the growing season, or when flowering was very much earlier in Carnamah (viz., following an early 'break' to the season), did this strain clearly outyield both Northam A and Geraldton. The seed yield of Dwalganup was generally inferior to that of the other strains. Factors affecting regeneration are discussed. Under low rainfall conditions, poorer germination-regulation of Carnamah, compared with Geraldton and Northam A, would be expected to result in poorer persistence unless offset by higher seed yields in the Carnamah strain.

A Method for obtaining Samples of the Population of Collembola (Symphypleona) in Pastures

1933 ◽  
Vol 24 (3) ◽  
pp. 351-352 ◽  
Author(s):  
J. Davidson ◽  
D. C. Swan
Keyword(s):  
Moisture Content ◽  
Total Population ◽  
Surface Soil ◽  
Relative Proportion ◽  
Subterranean Clover ◽  
Soil Surface ◽  
Trifolium Subterraneum ◽  
Food Plants ◽  
Simple Method ◽  
Factors Affecting

In our investigations on Smynthurus viridis, L., a study has been made of the population of this species, in an area of lucerne, at intervals of three and four days throughout the season.The density of the population of the species in a favourable pasture is markedly affected by the relative abundance of certain food-plants, especially leguminous species and particularly clovers such as subterranean clover (Trifolium subterraneum) and lucerne (Medicago sativa).The activity of the insect is intimately associated with the moisture of its environment, and the moisture content of the surface soil is one of the most important factors affecting the environmental conditions.Considering the habits of the insect, it was felt that the sweeping method would not give a reliable record of the total population in a given area of pasture. A sample obtained by sweeping with a net does not include individuals on or near to the surface of the soil. The relative proportion of individuals situated on or near the soil surface and those situated further up the plants varies considerably from time to time, according to the meteorological conditions, the growth of the herbage and the moisture content of the surface soil. It was necessary therefore to devise a simple method by means of which a more accurate record of the total population in a given area could be obtained.

Degradability of crude protein from clover herbages used in irrigated dairy production systems in northern Victoria

2001 ◽  
Vol 52 (3) ◽  
pp. 415 ◽  
Author(s):  
D. C. Cohen
Keyword(s):  
Protein Content ◽  
White Clover ◽  
Crude Protein ◽  
Nutritive Value ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Crude Protein Content ◽  
Persian Clover ◽  
Protein Supply ◽  
In Sacco

An in sacco (nylon bag) technique was used to estimate the degradability of dry matter (DM) and crude protein, and to estimate the effective rumen degradability of protein (ERDP), for 3 irrigated clover herbages. Pasture characteristics (nutritive values and leaf: stem ratios) were also described, and relationships to ERDP established. The nutritive value characteristics and degradabilities of white clover (Trifolium repens L.), Persian clover (Trifolium resupinatum L.), and subterranean clover (Trifolium subterraneum L.) were also compared for various regrowth periods (of 3, 4, 6, and 12 weeks). Nutritive value characteristics of clover herbages varied from 9.9 to 11.9 MJ/kg DM for metabolisable energy, 153 to 304 g/kg DM for crude protein, and 209 to 377 g/kg DM for neutral detergent fibre. The leaf: stem ratio correlated well with the crude protein content of the clovers, with herbages consisting of more leaf generally having superior crude protein content (R2 = 0.64, P < 0.001). The effective rumen degradability of protein for clover herbages ranged from 60 g/kg DM for mature (12 week regrowth) subterranean clover to 195 g/kg DM for vegetative (3 weeks regrowth) Persian clover. For clover herbages with a 3-week regrowth period, after initial cutting to 5 cm, and at ruminal outflow rates of 0.08/h, the effective rumen degradability of protein varied from 136 to 195 g/kg DM. A positive relationship between crude protein and ERDP (R2 = 0.82) suggested that ERDP could be estimated for clover herbages that have been previously assessed for crude protein content, obviating the need for in sacco studies. Calculated degradabilities were lower for all clovers when higher ruminal outflow rates were assumed. Using the metabolisable protein system, metabolisable protein supply and metabolisable protein in excess of animal requirements were calculated. Ruminal losses of nitrogen were also estimated for cows consuming white clover of varying regrowth periods in both early and late lactation. It was concluded that metabolisable protein supply is unlikely to limit production in these examples. At regrowth periods of 3 weeks, metabolisable protein contributions from microbial and dietary sources were similar, and twice that required by the animal. Ruminal losses of nitrogen were substantial and amounted to 66—23% of nitrogen intake. In the experiments reported here, if all of the energy required to excrete excess protein (as urea) could instead be used for the production of milk, cows may have produced 0.5mp;mdash;2.0 kg more milk per day. Such losses could potentially be reduced if the protein content and/or degradabilities of clover herbages were reduced, and/or energy rich supplements were offered.

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