Somatic Fusion for Breeding of Tetraploid Potatoes

From two tetraploid, one Transformed tetraploid, one triploid and 11 dihaploid clones of Solanum tuberosum somatic hybrids were produced by polyethylene glycol mediated somatic fusion. The inter-dihaploid clones comprised clones of agronomic value, homozygous doubled monohaploids, and in vitro selected clones resistant t0 Fusarium or Phytophthora toxins. Presumptive hybrids were enriched at the callus Stage in vitro by using differentiating media and by growth characteristics; further identification was performed by chromosome counting in vitro shoots and by isozyme analysis of in vitro plants. Final analysis was made from morphological characteristic of plant and tuber phenotypes. From 15 different combinations, 6009 plantlets have been regenerated. From five combinations, 310 reentrants were checked for hybrid nature by morphology and cytology and 88 by peroxidase and esterase isozyme analyses. Amongst these, from two combinations, a total of 17 different hybrids were confirmed by all methods. The procedures described are general enough to allow genome combination of interdihaploids resulting in tetraploids of practical breeding value.     

Production of an interspecific hybrid in Gypsophila by ovule-embryo culture

Summary We have succeeded in producing useful interspecific hybrid using ovule-embryo culture between Gypsophila paniculata L. Red Sea and G. manginii, an incompatible combination by ordinary cross breeding methods. The hybrid plant had double flowers with a color of pale purplish pink. Hybrid characteristics of the plant were firmed by observation of plant form, flower type, chromosome number and peroxidase isozyme patterns.     

The role of free space calcium in the basipetal transport of indole‐3‐acetic acid in sunflower hypocotyls 1

Calcium has been reported to be involved in the basipetal transport of indole‐3‐acetic acid (IAA). It has been suggested that basipetal transport of IAA requires the influx of Ca²⁺ into the cytoplasm from the cell wall free space and that Ca²⁺ acts as a second messenger. Experiments were conducted to determine the interaction of free space Ca²⁺ with the basipetal transport of IAA. Four day old sunflower (Helianthus annus L. cv ‘Russian Mammoth') seedlings grown in 0.20 strength Hoagland's solution were either left intact or excised below the cotyledonary node to remove the meristem, the source of IAA in the shoot. After removal of the node, the plants were treated with or without 500 μM IAA in lanolin paste. After 24 h, 3 mm segments were cut from the hypocotyls and incubated in KCl. Solution Ca²⁺ concentration, representing free space Ca²⁺, increased when the source of IAA was removed. Plants which were provided a source of IAA, either endogenously or exogenously, had low levels of free space Ca²⁺. In a separate experiment, segments of sunflower hypocotyls were incubated in KCl solutions with or without 10 μM IAA. Free space Ca²⁺ was lower when the segments were incubated in solutions containing IAA. It was concluded that basipetal IAA transport resulted in low levels of Ca²⁺ in the free space, which supports the hypothesis that basipetal IAA transport has a requirement for the influx of Ca²⁺ from the free space into the cytoplasm.     

Effect of molecular complexity and acidity of earthworm faeces humic fractions on glutamate dehydrogenase,glutamine synthetase,and phosphoenolpyruvate carboxylase in Daucus carota α II cells

Carrot cells were grown in cultures supplemented with two hormones [2,4-dichlorophenoxyacetic acid (2,4-D) and 6-benzylaminopurine (6BAP)] and two humic fractions extracted from earthworm faeces, one with high acidity and a low apparent molecular size (<3500) and the other with low acidity and a large molecular size. 2,4-D stimulated growth through an effect on cell enlargement, while the strongly acidic humic fraction (0.2 mg l^-1) and the weakly acidic fraction (1 mg l^-1) were both less effective. With 4–16 h of pre-incubation, the highly acid humic fraction, mainly alone, induced the best increase in protein content; the effect of the weakly acid humic fraction and the hormones was generally less important. The two humic fractions also differed in their influence on glutamate dehydrogenase activity. After 2 h of pretreatment, the highly acidic fraction increased glutamate dehydrogenase activity, while the other fraction did not affect it. After 4–16 h of pre-incubation, the activity of this enzyme was still not influenced by these humic fractions. The presence of the two hormones did not interfere with the humic matter effects. Glutamine synthetase activity was not affected by a pre-incubation of up to 4 h with the two humic fractions, but it was stimulated after 8–16 h of pre-incubation. A 2,4-D+6BAP mixture stimulated glutamine synthetase activity (from +12 to +50%). Again, the presence of the hormones did not interfere with the effects induced by the humic fractions. After 16 h of pre-incubation, phosphoenolpyruvate carboxylase activity was increased by the highly acidic humic fraction (+93%) and by both humic fractions together (+34%). An explanation of the different incubation times necessary for the humic fractions to exert stimulatory effects on these enzymes is proposed here. The regulatory properties of the strongly acidic humic fraction appeared to depend on the combination of high acidity (expecially carboxylic C) with low molecular size.     

Boron-Calcium Synergically Alleviates Aluminum Toxicity in Wheat Plants (Triticum aestivum L.)

The effects of B and Ca treatments on root growth, nutrient localization and cell wall properties in wheat ( Triticum aestivum L.) plants with and without Al stress were investigated. Seedlings were grown hydroponically in a complete nutrient solution for 7 d and then treated with B (0, 40 μM), Ca (0, 2,500 μM), and Al (0, 100 μM) in a 500 μM CaCl₂ solution for 8 d. The cell wall materials (CWM) were extracted with a phenol: acetic acid: water (2:1:1 w/v/v) solution and used for subsequent pectin extraction with trans -1,2-diami-nocyclohexane- N,N,N,N -tetraacetic acid (CDTA) and Na₂CO₃ solutions. Boron, Ca, and B + Ca treatments enhanced root growth by 19.5, 15.2, and 27.2%, respectively, compared to the control (pH 4.5). Calcium and B+Ca treatments enhanced root growth with Al stress by 43 and 54%, respectively, while B did not exert any effect. The amounts of CWM and pectin per unit of root fresh weight increased by Al treatment, whereas the Ca and B+Ca treatments slightly reduced the contents of these components. Seventy-four percent of total B, 69% of total Ca, and 85% of total Al were located in the cell wall in the B, Ca, and Al treatments, respectively and 32% of total B, 33% of total Ca, and 33% of total Al were located in the CDTA-soluble and Na₂CO₃-soluble pectin fractions. A more conspicuous localization of B was observed in the presence of Al. Aluminum treatment markedly decreased the Ca content in the cell wall as well as pectin fractions, mainly in the case of the CDTA-soluble pectin fraction. Boron + Ca treatment decreased the Al content in the cell wall and pectin fractions compared to the Ca treatment alone in the presence of Al. It is concluded that the B+Ca treatment enhanced root growth and, B and Ca uptake, and helped to maintain a normal B and Ca metabolism in the cell walls even in the presence of Al.     

Pesticide toxicity using protozoans as test organisms

Summary A toxicity test using protozoa as test organisms was devised for pesticides. Two different methods were used, the most probable number method and the absorbance method (based on measurement of protozoa growth through absorbance). The ciliates Colpoda cucullus and Blepharisma undulans and the flagellate Oikomonas termo were isolated from different biological starter cultures and tested with the herbicides Chlorex, MCPA, dichlorprop and Matrigon, the fungicide Benlate, and the insecticide Sumicidin. The protozoans showed quite different sensitivities to the pesticides, using 9-h lethal concentrations (LC₅₀ and LC₁₀) as criteria. The 9-h LC₅₀ (concentration at which 50% of the protozeon population has died after 9 h of incubation) ranged from 0.7 ppm for Benlate to 40000 ppm for Chlorex. The usual soil application rates of Chlorex, MCPA, and Benlate were toxic to some of the organisms.     

Effects of organic manure and NPK fertilization on earthworm activity in an Oxisol

The effects of fertilization with N, P, K, and organic manure (alone or in combination) on earthworm populations, biomass, and casting activity were measured in a cultivated soil (organic C 1.5%, annual rainfall 2000–2300 mm). These applications of fertilizer caused significant increases in earthworm numbers, biomass, and casts. N alone or in combination with P and K also influenced these earthworm parameters significantly. The inorganic NPK fertilizer in combination with organic manure had a significantly greater effect on earthworm activities than NPK fertilizer alone, and therefore the addition of organic matter appears advisable in order to obtain maximum benefits from NPK fertilizer in this soil.     

Antipruritic activity of extracts of Humulus scandens, the combinations of bioactive flavonoids

The antipruritic effects of the ethanol fractions of Humulus scandens on the 4-AP (4-aminopyridine)-induced and chloroquine-induced scratching in ICR mice were examined. The 40% ethanol fractions of H. scandens suppressed both the 4-AP- and chloroquine-induced scratching behavior, which significantly inhibited degranulation of rat peritoneal mast cell and antigen-stimulated histamine release. Further studies proved that the 40% ethanol fractions of H. scandens decreased the content of IL4 in serum of chloroquine-induced scratching ICR mice. The results suggest that the 40% ethanol fractions of H. scandens has antipruritic effects on both antihistamine-resistant and -sensitive pruritus.