In vivo interspecific pollination success between Pinus radiata, P. maximinoi, P. oocarpa and P. tecunumanii

Abstract

The objective of the study was to investigate in vivo interspecific pollination success between Pinus radiata, P. maximinoi, P. oocarpa and P. tecunumanii. Pinus radiata was control pollinated with pollen lots of P. maximinoi, P. oocarpa and P. tecunumanii in a P. radiata seed orchard at Karatara (Southern Cape, South Africa). Pollination success was determined by counting the number of visible ovules, pollen grains inside and outside P. radiata ovules, as well as pollen tubes visible inside P. radiata ovules. Conelets were harvested and studied at eight time intervals, including 24 h after pollination, and weekly for 7 weeks after pollination. Histology studies with a standard fixation-dehydration-embedding sequence and paraffin wax method were used to determine the number of visible pollen grains inside versus outside the ovules and number of pollen tubes. Results indicated that pollen grains did sift through the cone scales within 24 h after pollination. However, P. radiata differed significantly (time by type of cross interaction) from the other three hybrid combinations in terms of number of visible ovules, visible pollen grains inside and outside of the ovules as well as pollen tubes, confirming limited interspecific hybridisation success. Future studies need to determine the percentage of fertile ovules in cross combination as a tool in predicting pollination success.

Keywords

Pollen tubes / Pollen grains / Hybridization / Reproductive barriers / Pinus radiata

References

[1] Bramlett DL (1981) Effectiveness of wind pollination in seed orchards. In: Franklin EC (eds) Pollen management handbook, USDA and Southern Forest Tree Improvement Committee, Agriculture Handbook nr. 587, Chapter 2

[2] Bramlett DL, O’Gwynn CH (1981) Controlled pollination. In: Franklin ED (ed) Pollen management handbook. Agriculture Handbook Number 587, United States Department of Agriculture, Washington, pp 44–51

[3] Brown S, Bridgewater F. Observations on pollination in loblolly pine. Can J For Res, 1987, 17: 299-303.

[4] Cain S. The identification of species in fossil pollen of Pinus by size-frequency determinations. Am J Bot, 1940, 27: 301-308.

[5] Caron G-E, Powell GR. Pollen sizing in Jack pine (Pinus banksiana Lamb.) with a hemocytometer. Silvae Genetica, 1995, 44: 96-103.

[6] Coetzee J (1982) Inleidende kursus in plantkundige mikrotegnieke [Introductory course in botanical microtechnics]. Stellenbosch University, Department of Botany, South Africa, p 80

[7] Coura R, Prolla JC, Meurer L, Ashton-Prolla P. An alternative protocol for DNA extraction from formalin fixed and paraffin wax embedded tissue. J Clin Pathol, 2005, 58(8): 894-895.

[8] Critchfield WB (1975) Interspecific hybridisation in Pinus: a summary review. Symposium on interspecific and interprovenance hybridisation I forest trees. In: Fowler DP, Yeatman CY (ed) Proceedings 14th meeting, Canada tree improvement association part II. doi: https://www.treesearchfs.fed.us/pubs/32752

[9] Dafni A, Pacini E, Nepi M. Dafni A, Kevan PG, Husband BC. Pollen and stigma biology. Practical pollination biology, 2005, Cambridge: Enviroquest Ltc. 590

[10] Dungey HS, Carson MJ, Low CB, King NG. Potential and niches for inter-specific hybrids with Pinus radiata in New Zealand. N Z J For Sci, 2003, 33: 295-318.

[11] Dvorak WS. One-year provenance/progeny results of Pinus tecunumanii from Guatemala established in Brazil and Colombia. Commonw For Rev, 1985, 64: 57-65.

[12] Dvorak WS, Jordon AP, Hodge GP, Romero JL. Assessing evolutionary relationships of pines in the Oocarpae and Australes subsections using RAPD markers. New For, 2000, 20: 163-192.

[13] Dvorak WS, Potter KM, Hipkins VD, Hodge GR. Genetic diversity and gene exchange in Pinus oocarpa, a Mesoamerican pine with resistance to the pitch canker fungus (Fusarium circinatum). Int J Plant Sci, 2009, 170: 609-626.

[14] Ellstrand NC. Is gene flow the most important evolutionary force in plants?. Am J Bot, 2014, 101: 737-753.

[15] Feder N, O’Brien TP. Plant microtechnique: some principles and new methods. Am J Bot, 1968, 55(1): 123-142.

[16] Fernando DD. The pine reproductive process in temperate and tropical regions. New For, 2014, 45(3): 333-352.

[17] Fernando DD, Long SM, Sniezko RA. Sexual reproduction and crossing barriers in white pines: the case between Pinus lambertiana (sugar pine) and P. monticola (western white pine). Tree Genet Genomes, 2005, 1: 143-150.

[18] Funda T, Liewlaksaneeyanawin C, El-Kassaby YA. Determination of paternal and maternal parentage in lodgepole pine seed: full versus partial pedigree reconstruction. Can J For Res, 2014, 44(9): 1122-1127.

[19] Greenwood MS. Reproductive development in loblolly pine: I. The early development of male and female strobili in relation to the long shoot growth behavior. Am J Bot, 1980, 67: 1414-1422.

[20] Greenwood MS. Gene exchange in loblolly pine: the relation between pollination mechanisms, female receptivity and pollen viability. Am J Bot, 1986, 73: 1433-1451.

[21] Griffin AR, Lindgren D. Effect of inbreeding on production of filled seed in Pinus radiata—experimental results and a model of gene action. Theor Appl Genet, 1985, 71: 334-343.

[22] Hagman M. Incompatibility in forest trees. Proc R Soc Lond B, 1975, 188: 313-326.

[23] Hall JP, Brown IR. Embryo development and yield of seed in Larix. Silvae Genetica, 1977, 26: 77-84.

[24] Ham H, Botha A-M, Kanzler A, du Toit B (2017a) Pinus radiata interspecific hybridisation: environmental conditions inside pine pollination bags as a potential hybridisation barrier. Submitted to Annales of Forest Research, April 20th

[25] Ham H, Botha A-M, Kanzler A, du Toit B (2017b) Pinus radiata hybridisation: pollen tube elongation and pollen grain size as possible reproductive barriers. Accepted but subjected to final corrections by iForest, April 30th

[26] Ham H, du Plessis A, le Roux SG. Micro computer tomography (microCT) as a tool in Pinus tree breeding: case study. N Z J For Sci, 2017, 47(1): 2-8.

[27] Harushima Y, Nakagahra M, Yano M, Sasaki T, Kurata N. A genome-wide survey of reproductive barriers in an interspecific hybrid. Genetics, 2001, 159: 883-892.

[28] Huyn SK. Interspecific hybridization in pines with the special reference to Pinus rigida x taeda. Silvae Genetica, 1976, 25: 188-191.

[29] Johnsson H. Contributions to the genetics of empty grains in the seed of pine (Pinus sylbestris). Silvae Genetica, 1976, 25: 10-15.

[30] Konar R, Oberoi Y. Recent work on reproductive structures of living conifers and taxads—a review. Bot Rev, 1969, 35: 89-116.

[31] Kormanik PP. Kraus J. Conelet abortion in pines. Seed yield from southern pine seed orchards, 1974, Macon: Georgia Forest Research Council 42 48

[32] Lanner RM. Needed: a new approach to the study of pollen dispersion. Silvae Genetica, 1966, 15: 50-52.

[33] Lill BS. Ovule and seed development in P. radiata D. Don: post meiotic development, fertilisation and embryogeny. Can J Bot, 1976, 54: 2141-2154.

[34] Lindgren D (1975) The relationship between self-fertilization, empty seeds and seeds originating from selfing as a consequence of polyembryology. Studia Forestalia Suecica 126

[35] Little TM, Hills FJ. Statistical methods in agricultural experimentation, 1978, Davis: University of California.

[36] Major JE, Mosseler A, Johnsen KH, Rajora OP, Barsi DC, Kim K-H, Park J-M, Campbell M. Reproductive barriers and hybridity in two spruces, Picea rubens and Picea mariana, sympatric in eastern North America. Can J Bot, 2005, 83: 163-175.

[37] Mathews S, Kramer EM. The evolution of reproductive structures in seed plants: an r-examination based on insights from developmental genetics. New Phytol, 2012, 194: 910-923.

[38] McWilliam JR. The role of the micropyle in the pollination of Pinus. Bot Gaz, 1958, 2: 109-117.

[39] McWilliam JR. Interspecific incompatibility in Pinus. Am J Bot, 1959, 46: 425-433.

[40] Mert C, Soylu A. Flower and stamen structures of male-fertile and male-sterile chestnut (Castanea sativa Mill.) cultivars. J Am Soc Hortic Sci, 2006, 131: 752-759.

[41] Moody WR, Jett JB. Effects of pollen viability and vigor on seed production of loblolly pine. South J Appl For, 1990, 14: 33-38.

[42] Moran GF, Griffin AR. Non-random contribution of pollen in polycrosses of Pinus radiata D. Don. Silvae Genetica, 1985, 34: 117-121.

[43] Moran GF, Bell JC, Matheson AC. The genetic structure and levels of inbreeding in a Pinus radiata D. Don seed orchard. Silvae Genetica, 1980, 29: 190-193.

[44] Nel A, van Staden J. Micro-fibre pollination bags and high viability Pinus patula pollen enhance cone survival and seed set during controlled pollination. S Afr J Bot, 2003, 69: 469-475.

[45] Nel A, van Staden J. Pollen morphological features of temperature on pollen germination of various Pinus species. S Afr J Bot, 2005, 71: 88-94.

[46] O’Leary S, von Aderkas P. Post pollination drop production in hybrid larch is not related to the diurnal pattern of xylem water potential. Trends Ecol Evol, 2006, 20: 61-66.

[47] Ott RL, Longnecker M. An introduction to statistical methods and data analysis, 2001 5 Belmont: Duxbury Press 1273

[48] Owens JN, Bruns D. Western white pine (Pinus monticola Dougl.) reproduction: I. Gametophyte development. Sex Plant Reprod, 2000, 13: 61-74.

[49] Owens JN, Fernando DD. Pollination and seed production in western white pine. Can J For Res, 2007, 37: 260-275.

[50] Owens JN, Simpson SJ, Molder M. Sexual reproduction of Pinus contorta. I. Pollen development, the pollination mechanism, and early ovule development. Can J Bot, 1981, 59: 1828-1843.

[51] Owens JN, Bennett J, L’Hirondelle S. Pollination and cone morphology affect cone and seed production in lodgepole pine seed orchards. Can J For Res, 2005, 35: 383-400.

[52] Plomoin C, Chagné D, Pot D, Kumar S, Wilcox PL, Burdon RD, Prat D, Peterson DG, Paiva J, Chaumeil P, Vendramin GG, Sebastiani F, Nelson CD, Echt CS, Savolainen O, Kubisiak TL, Cervera MT, de Marìa N, Islam-Faridi MN. Kole C. Pines. Genome mapping and molecular breeding in plants, forest trees, 2007, Berlin: Springer 220

[53] Santos-del-Blanco L, Climent J. Costs of female reproduction in a conifer tree: a whole-tree level assessment. J Ecol, 2014, 102(5): 1310-1317.

[54] Sarvas R. Investigations on the flowering and seed crop of Pinus sylvestris. Commun Inst Fenn, 1962, 53: 1-198.

[55] Sass EJ. Botanical microtechnique, 1958, Iowa Ames: Iowa State University Press 228

[56] Schwendemann AB, Wang G, Mertz ML, McWilliams RT, Thatcher SL, Osborn JM. Aerodynamics of saccate pollen and its implications for wind pollination. Am J Bot, 2007, 94: 1371-1381.

[57] Shapiro SS, Wilk MB. An analysis of variance test for normality (complete samples). Biometrika, 1965, 52: 591-611.

[58] Slee MU, Abbott DC. Pollination investigations for production of the hybrid between slash and Caribbean Pines. South Afr For J, 1990, 152: 7-16.

[59] Solga MJ, Harmon JP, Ganguli AC. Timing is everything: an overview of phenological changes to plants and their pollinators. Nat Areas J, 2014, 34: 227-234.

[60] Stephenson AG. Flower and fruit abortion: proximate causes and ultimate functions. Ann Rev Ecol Syst, 1981, 12: 253-279.

[61] Sweet GB. Pollination in Pinus radiata. N Z J For Sci, 1977, 7(1): 21-34.

[62] Sweet GB, Thulin IJ. The abortion of conelets in Pinus radiata. N Z J For, 1969, 14: 59-67.

[63] Tjoel DM (1983) AGS (Alcian Green Safranin)—a simple differential staining of plant material for the light microscope. In: Royal Microscopical Society (ed) Proceedings—royal microscopical society, vol 18, pp 149–151

[64] Tomlinson P. Functional morphology of saccate pollen in conifers with special reference to the Podocarpaceae. Int J Plant Sci, 1994, 155: 699-715.

[65] Tomlinson P, Braggins J, Rattenbury J. Contrasted pollen capture mechanisms in Phyllocladaceae and certain Podocarpaceae (Coniferales). Am J Bot, 1997, 84: 214-223.

[66] Trigiano RN, Gray DJ. Plant tissue culture, development, and biotechnology, 2011, Boca Raton: CRC Press 608

[67] Varis S, Santanen A, Pakkanen A, Pulkkinen P. The importance of being the first pollen in the strobili of Scots pine. Can J For Res, 2008, 38: 2976-2980.

[68] Williams CG. Conifer reproductive biology, 2009, Berlin: Springer 172

[69] Winsor L (1994) Tissue processing. Laboratory histopathology. Churchill Livingstone, New York. Available online: https://www.researchgate.net/file.PostFileLoader.html?id=5536a4d8d767a649648b4575&assetKey=AS%3A273761889128455%401442281329466. Assessed 20 Nov