Selection of efficient VA mycorrhizal fungi for Casuarina equisetifolia?second screening

Abstract

Application. Casuarina equisetifolia L. is a tropical woody dicotyledonous tree species extensively used for fuel, land reclamation, erosion control, afforestation and waste land development in many tropical countries. One of the limiting factors in the use of this species is that it grows slowly in the nursery and in the initial stages of establishment. The present study showed that the growth of Casuarina equisefifolia can be stimulated through inoculation with efficient VAM fungi. Inoculation with efficient VAM fungi will result in healthy and vigorously growing seedlings which will establish better when planted in the field site.Abstract. An investigation was carried out to screen and select efficient vesicular arbuscular mycorrhizal (VAM) fungi for inoculating the forest tree species, Casuarina equisetifolia. The seedlings were inoculated with 10 different VAM fungi, obtained from various sources. Inoculated seedlings generally had greater plant height, stem girth, biomass and P content than uninoculated plants. They also had more mycorrhizal root colonization and spore numbers in root zone soil. C. equisetifolia seedlings responded best (in biomass) to inoculation with Glomus mosseae (Nicolson and Gerdemann) Gerdemann and Trappe, closely followed by Acaulospora laevis Gerdemann and Trappe and G. fasciculatum (Thaxter Sensu Gerdemann) Gerdemann and Trappe; all the three being statistically on par with each other.

Lack of competition between Frankia and Glomus for infection and colonization of roots of Casuarina equisetifolia (L.)

“…There are no detailed studies of Acaulospora and Gigaspora (El-Giahmi, Nicolson & the processes by which Casuarina roots become Daft, 1976;Rose, 1980;Daft, Clelland & Gardner, infected by AM fungi. By contrast, infection of 1985 ; Vasanthrakrishna & Bagyaraj, 1993). All three Casuarina roots by Frankia has been studied in some associations have been found on plants in some detail.…”

Frankia Nodulation, Mycorrhization and Interactions Between Frankia and Mycorrhizal Fungi in Casuarina Plants

“…Arbuscular mycorrhizal (AM) colonization ranges from 10 to 70% while EM ranges from 10 to 50% in Casuarina plants (Gardner 1986;Theodorou and Reddell 1991;Vasanthakrishna and Bagyaraj 1993;Subba-Rao and Rodriguez-Barrueco, 1995;Vasanthakrishna et al 1995;Singh et al 1998;He et al 2004He et al , 2005. The effectiveness and AM colonization through various AM species are consistent with different Casuarina species.…”

“…For example, two isolates of Pisolithus (H4111) and Scleroderm (H4314) could only induce a very low (1.7-2.3%) root colonization in 3-month-old C. equisetifolia roots (Dell et al 1994). In the same experiment, another isolate of Sources : Rose 1980;Gardner1986;Theodorou and Reddell 1991;Vasanthakrishna and Bagyaraj 1993;Vasanthakrishna et al 1995 Pisolithus (H4458) was unable to form EMs and the Scleroderm (H4151) isolate has even resulted in the death of C. equisetifolia seedlings (Dell et al 1994). In contrast, Duponnois et al (2003) recently found that Pisolithus and Scleroderina isolates did form EMs on C. glauca under axenic conditions, but without the appearance of the typical Hartig net.…”

“…Mycorrhizal colonization and spore numbers were greater in the root zone soil (Vasanthakrishna and Bagyaraj 1993;Vasanthakrishna et al 1995). Inoculated C. equisetifolia plants displayed greater plant height, biomass, and P and Zn contents.…”

“…In addition, Casuarina root systems can associate with either arbuscular mycorrhizal (AM) fungi, ectomycorrhizal (EM) fungi or both to form mycorrhiza (Warcup 1980;Gauthier et al 1983;Gardner 1986;Reddell et al 1986;Theodorou and Reddell 1991;Vasanthakrishna and Bagyaraj 1993;Vasanthakrishna et al 1994aVasanthakrishna et al , 1994bVasanthakrishna et al , 1995Subba-Rao and Rodriguez-Barrueco 1995;Reddell et al 1997;Osundina 1998;Singh et al 1998;Mark et al 1999;Wang and Qiu 2006), which helps their host plants to access soil nutrients and water. Some Casuarina species, including C. cunninghamiana, C. equisetifolia and C. glauca, even have the capacity to form cluster roots, which specialize in phosphorus (P) uptake from the soil (Diem 1996;Arahou and Diem 1997;Reddell et al 1997;Diem et al 2000;Zaïd et al 2003;Lambers et al 2006).…”