The influence of boron and copper deficiency upon infection byErysiphe graminis D.C., the powdery mildew, in wheat var. kenya

Abstract

the P o w d e r y Mildew, in w h e a t var. Kenya [~¢troducXionWhile the influence of micronutrients upon the susceptibility or resistance of a host plant to fungal infections has not been studied extensively, plant pathology texts .2 do draw attention to these relationships, as do more specialised works on micronutrients s 9. F o r s y t h ' s 6 work clearly shows t h a t rust resistance can be v e r y complex and that even non-nutrients such as D D T can increase the susceptibility of resistant varieties. As long ago as 1930, E a t o n 5 reported upon the influence of boron deficiency upon the resistance of barley to the obligate parasite Erysiphe gmm~nis. In the absence of boron, infection was extremely severe. No information regarding the action of copper appears to exist, although the addition of manganese to the soil significantly reduces the rate of infection. 3 In South Africa, E. grami~is has been reported extensively, but it is not of common occurrence, being mainly found infecting wheat and barley on irrigated lands 1. ExperimentalAn unheated glasshouse filled with sand-culture experiments involving wheat var. K e n y a became infected with E. graminis D. C. The source of the infection could not be traced, but it is presumed that the spores were air borne, and all the wheat plants became infected eventually, the fungus being readily identifiable b y its vegetative characteristics, especially its large oidiospores.The infection was associated with v e r y changeable weather, warm days alternating with periods of sudden severe cold. The fungus spread rapidly over all the boron-deficient plants, less rapidly over copper, m o l y b d e n u m and manganese-deficient ones and slowly over the controls which received fullbalanced mineral nutrition.One group of plants was strictly comparable. These were plants of wheat grown in sand culture at the rate of three per 14-cm. pot. They were irrigated with a modified R o b b i n s solution 7, the deficient cultures lacking only this specific element. The plants were allowed to grow to full ear, which took a period of 14 weeks in the case of the control.

Role of nutrients in controlling plant diseases in sustainable agriculture. A review

“…(Bolle-Jones and Hilton, 1956). It was also observed that in B-deficient wheat plants, the disease severity was several-fold higher than that in B-sufficient plants, with the fungus spreading more rapidly than in B-sufficient plants (Schutte, 1967).…”

Soybean Seed Composition Constituents as Affected by Drought andPhomopsisin Phomopsis Susceptible and Resistant Genotypes

“…For example, potassium (Spann & Schumann 2011) and Zn (Bolle-Jones & Hilton 1956) deficiency resulted in high cell wall leakage of sugar and amino acid concentrations to leaf apoplast, leading to easy penetration by pathogens. Boron deficiency resulted in higher fungal infection (Schutte 1967) and low content of Ca in plant tissue, increasing cell wall leakage of sugars and amino acids from cytoplasm to apoplast. It was found that Ca is involved in the stability of cell wall through polygalacturonates, which are required for the middle lamella for cell wall synthesis.…”

Soybean Seed Phenolics, Sugars, and Minerals Are Altered by Charcoal Rot Infection in MG III Soybean Cultivars

“…It was found that K and Zn deficiencies resulted in high cell wall leakage of sugar and amino acid concentrations to leaf apoplast, allowing the pathogen to penetrate the cell [38] [40]. Also, it was found that B deficiency led to higher fungal infection and low Ca content in plant tissue, resulting in cell wall leakage of sugars and amino acids from cytoplasm to apoplast [41]. Calcium has a role in stability of cell wall through polygalacturonates and in the activity of enzymes like polygalacturonase which dissolves the middle lamella, and both of these two processes were found to be inhibited by Ca deficiency.…”

“…Previous research showed that minerals such B, Mn, and Cu play a major role in phenolics and lignin synthesis [37] [39] and in cell wall and membrane integrity. Deficiencies of K and Zn resulted in high cell wall leakage of sugar and amino acid to leaf apoplast, allowing the pathogen to penetrate the cell [38] [40]; B deficiency led to higher fungal infection [41]; low Ca content in plant tissue re-sulted in cell wall leakage of sugars and amino acids from cytoplasm to apoplast; and Cu deficiency led to impairment of defense compound synthesis, accumulation of soluble carbohydrates, and reduced lignin synthesis, resulting in lower disease resistance [38].…”