Growth characteristics and reproductive output of dwarf mistletoe-infected Juniperus polycarpos in Iran

Abstract

Dwarf mistletoes are parasitic flowering plants that infect conifers, resulting in substantial loss of growth and mortality. Recently, forest managers in Iran are contemplating whether infection of Juniperus polycarpos C. Koch forests by dwarf mistletoe, Arceuthobium oxycedri (DC.) M. Bieb, influences tree vigor and contributes to insufficient natural regeneration. The present study aimed at assessing the severity of infection and its impact on growth and reproductive output of J. polycarpos. Infected and uninfected trees (n =20 each) were selected for assessment of diameter, height, crown area, and crown volume as well as quantity and quality of cones and seeds. The severity of infection of trees was determined by Hawksworth’s 6-class dwarf mistletoe rating (DMR) system. The DMR system revealed that 40% of the infected sample trees were lightly infected (DMR =1–2) and 60% were moderately infected (DMR =3–4). Growth characteristics did not differ significantly (p > 0.05) between infected and uninfected trees. However, moderate infection affected the reproductive output of J. polycarpos by significantly (p<0.05) reducing the mean number of cones per unit area of the crown, increasing the number of damaged seeds, and reducing seed size and seed germination capacity. We conclude that reproductive output of J. polycarpos is more sensitive than growth characters to moderate infection by juniper dwarf mistletoe, and this might partly account for poor natural regeneration.

Keywords

conifers / Greek juniper / forest health / parasitic plant / seed size

References

[1] Ahani H, Jalilvand H, Hosseini-Nasr SM, Soltani KH, Ghazi MR, Mohammadzadeh H. Reproduction of Juniperus polycarpos in Khorasan Razavi, Iran. Forest Science and Practice, 2013, 15(3): 231-237.

[2] Akkol EK, Guvenc A, Yesilada E. A comparative study on the antinociceptive and anti-inflammatory activities of five Juniperus taxa. Journal of Ethnopharmacology, 2009, 125(2): 330-336.

[3] Aukema JE, Martinez del Rio C. Levey DJ, Silva WR, Galetti M. Mistletoes as parasites and seeddispersing birds as disease vectors: current understanding, challenges, and opportunities. Seed Dispersal and Frugivory: Ecology, Evolution and Conservation. 2002, Oxfordshire, UK: CAB International Press, 99 110

[4] Bazzaz FA, Ackerly DD, Reekie EG. Fenner M. Reproductive allocation in plants. Seeds: the Ecology of Regeneration in Plant Communities. 2000, Wallingford/New York: CABI Publishing, 1 29

[5] Bowie M, Ward D. Water and nutrient status of the mistletoe Plicosepalus acaciae parasitic on isolated Negev Desert populations of Acacia raddiana differing in level of mortality. Journal of Arid Environments, 2004, 56: 487-508.

[6] Carlo TA, Aukema JE. Female-directed dispersal and facilitation between a tropical mistletoe and a dioecious host. Ecology, 2005, 86(12): 3245-3251.

[7] Dean WRJ, Midgley JJ, Stock WD. The distribution of mistletoes in South Africa: patterns of species richness and host choice. Journal of Biogeography, 1994, 21(5): 503-510.

[8] Farjon A. A monograph of Cupressaceae and Sciadopitys. 2005, Kew: Royal Botanic Gardens Press

[9] Geils BW, Hawksworth FG. Geils BW, Tovar JC, Moody B. Damage, effects, and importance of dwarf mistletoes. Mistletoes of North American Conifers, 2002 1 5

[10] Glatzel G, Geils BW. Mistletoe Ecophysiology: host parasite interactions. Botany, 2009, 87: 10-15.

[11] Green AK, Ward D, Griffiths ME. Directed dispersal of mistletoe (Plicosepalus acaciae) by Yellow-vented Bulbuls (Pycnonotus xanthopygos). Journal of Ornithology, 2009, 150: 167-173.

[12] Gregg JW, Ehleringer JR. 1990. Is mistletoe presence dependent on host quality?. Bulletin of the Ecological Society of America, 71: 173 p.

[13] Hawksworth FG. The 6-class dwarf mistletoe rating system. USDA Forest Service, Rocky Mountain Forest and Range Experiment Station, Fort Collins, Colorado, 1977

[14] Hawksworth FG, Wiens D. Dwarf mistletoe: biology, pathology and systematics, 1996

[15] Kenaley SC, Mathiasen RL, Daugherty CM. Selection of dwarf mistletoe-infected ponderosa pines by Ips species (Coleoptera: Scolytidae) in northern Arizona. Western North American Naturalist, 2006, 66(3): 279-284.

[16] Korouri AAS, Khoshnevis M, Matinizadeh M. Comprehensive studies of Juniperus species in Iran. Forest, Range and Watershed Management Organization, 2012

[17] Lamien N, Boussim JI, Nygard R, Ouédraogo JS, Odén PC, Guinko S. Mistletoe impact on Shea tree (Vitellaria paradoxa C.F. Gaertn.) flowering and fruiting behaviour in savanna area from Burkina Faso. Environmental and Experimental Botany, 2006, 55: 142-148.

[18] Okubamichael DY, Griffiths ME, Ward D. Host specificity, nutrient and water dynamics of the mistletoe (Viscum rotundifolium) potential host species in the Kalahari of South Africa. Journal of Arid Environments, 2011, 75: 643-649.

[19] Panvini AD, Eickmeier WG. Nutrient and water relations of the mistletoe Phoradendron leucarpum (Viscaceae): How tightly are they integrated?. American Journal of Botany, 1993, 80(8): 872-878.

[20] Sarangzai AM, Khan N, Wahab M, Kakar A. New spread of dwarf mistletoe (arceuthobium oxycedri) in Juniper forests, Ziarat, Balochistan, Pakistan. Pakistan Journal of Botany, 2010, 42(6): 3709-3714.

[21] Schaffer B, Hawksworth FG, Jacobi WR. Effects of Comandra blister rust and dwarf Mistletoe on cone and seed production of Lodgepole pine. Plant Disease, 1983, 67(2): 215-217.

[22] Scott JM, Mathiasen RL. Assessing growth and mortality of Bristlecone pine infected by dwarf mistletoe using dendrochronology. Journal of Forest Science, 2012, 58(4): 366-376.

[23] Seel WE, Cooper RE, Press MC. Growth, gas exchange and water use efficiency of the facultative hemi-parasite Rhinanthus minor associated with hosts differing in foliar nitrogen concentration. Physiologia Plantarum, 1993, 89: 64-70.

[24] Shaw DC, Huso M, Bruner H. Basal area growth impacts of dwarf mistletoe on western hemlock in an old-growth forest. Canadian Journal of Forest Research, 2008, 38: 576-583.

[25] Shen TY, Odén PC. Fumarase activity as a quicker vigor test for Scots pine (Pinus sylvestris L.) seeds. Seed Science and Technology, 2000, 28: 825-835.

[26] Singh P. Eastern Dwarf Mistletoe Arceuthobium-Pusillum on Black Spruce in Newfoundland Canada. Phytopathology, 71. 1981, Contact: Singh P. New Found Land Forest Res. Centre, Canadian Forestry Service, St John’s, NFLD, CANADA

[27] Singh P, Carew GC. Impact of eastern dwarf mistletoe in black spruce forests of Newfoundland. European Journal of Forest Pathology, 1989, 19: 305-322.

[28] Slobodnik B, Gutternberger H. Ovule, megaspores and female gametophyte formation in Larix decidua Mill. (Pinaceae). Acta Biologica Cracoviensia Serie Botanique, 2000, 42(2): 93-100.

[29] Sproule A. Impact of dwarf mistletoe on some aspects of the reproductive biology of jack pine. The Forestry Chronicle, 1996, 72(3): 303-306.

[30] Stanton S. The differential effects of dwarf mistletoe infection and broom abundance on the radial growth of managed ponderosa pine. Forest Ecology and Management, 2006, 223: 318-326.

[31] Stanton S. Effects of dwarf mistletoe on climate response of mature ponderosa pine trees. Tree-Ring Research, 2007, 63: 69-80.

[32] Tigabu M, Fjellström J, Odén PC, Teketay D. Germination of Juniperus procera seeds in response to stratification and smoke treatments, and detection of insect-damaged seeds with VIS + NIR spectroscopy. New Forests, 2007, 33: 155-169.

[33] Wulff RD. Kigel J, Galili G. Environmental maternal effects on seed quality and germination. Seed development and germination. 1995, New York/Basel/Hong Kong: Marcel Dekker Inc., 491 505