Reproduction
REPRODUCTIVE BIOLOGY
During the last 45 years particular attention was paid to the reproductive systems active in endemic and indigenous New Zealand grasses, in the belief that such studies would reflect in some measure the morphological variation encountered in the field and in the herbarium. A series "Breeding Systems in New Zealand Grasses" was published in 12 parts, but for many species data on compatibility reactions were included in other studies. In all, the breeding systems of about 60 species among 20 genera are known, and among them self-compatible hermaphroditism is at a very high frequency. Dioecism is in five species of Poa and in Spinifex sericeus. Andromonoecism characterises all species of Hierochloe in New Zealand, gynomonoecism occurs in three species of Poa, and gynodioecism is present in all species of Cortaderia except C. turbaria from Chatham Is. Self-compatibility is easily recognised in chasmogamous-cleistogamous Dichelachne and Microlaena; two species of this latter also produce cleistogenes. Cleistogamy is certain for two species of Festuca, and two of Deyeuxia, but only tentatively suggested for some Poa spp.
No endemic species is known to be apomictic, but Poa, where apomictic phenomena abound (Anton and Connor 1995), has not been subject to any critical embryological examination. For the other polytypic genera, Chionochloa - a genus with periodic flowering and mast seeding - and Rytidosperma, self-compatibility is known in about seven species of the former, but none of the latter has been subject to experiment.
Papers listed below deal with the reproductive biology of native species, but much is known about the breeding systems of naturalised grasses, e.g., the genetics of incompatibility in Lolium and Phalaris; autonomous precocious apomixis in Cortaderia jubata; self-compatibility in Vulpia spp. and Briza spp.; monoecism in Zizania latifolia; cleistogamy in Sieglingia and in Nassella spp. especially where N. neesiana also forms cleistogenes in the axils of leaves at the base of a tiller. Details for these and other taxa are in Connor (1979, 1981, 1987).
In a review of the reproductive biology of grasses Connor (1979) continued to express the concern that C. E. Hubbard of Kew had raised twenty-five years earlier: the omission of the description of the flowers in many treatments and in many new species definitions. Surprisingly, this failure persists, often associated with carpological deficiencies; yet the flowers and their resultant seeds eventually validate taxonomic predictions. We make no apology for the floral descriptions here which may not be needed by some users but which are vital to floral biologists and evolutionists, and after all only complete the species description. In this Flora we endeavour, especially for endemic and indigenous taxa, to include data on lodicules, stamens, and gynoecia, their dimorphism and heteromorphism where these occur, and their distribution between flowers when they are separate. We endeavour to clarify the reproductive biology of taxa where uncertainty existed, and indicate the presence of cleistogamy, protogyny, chasmogamy, asexuality, and sterility where these occur.
Anton, A. M. and H. E. Connor. 1995: Floral biology and reproduction in Poa. Aust. J. Bot. 43: 577-599.
Connor, H. E. and A. B. Cook. 1952: Note on the breeding system of Dichelachne crinita (Linn. f.) Hook. f. in New Zealand. N.Z. J. Sci. Tech. A34: 369-371.
Connor, H. E. and A. B. Cook. 1955: The breeding system of New Zealand fescue-tussock Festuca novae-zelandiae (Hack.) Cockayne. N.Z. J. Sci. Tech. A37: 103-105.
Connor, H. E. 1957: Breeding systems in some New Zealand grasses. N.Z. J. Sci. Tech. A38: 742-751.
Connor, H. E. and E. D. Penny. 1960: Breeding systems in New Zealand grasses II. Gynodioecy in Arundo richardii. N.Z. J. Agric. Res. 3: 725-727.
Connor, H. E. 1960: Breeding systems in New Zealand grasses. III. Festuceae, Aveneae, Agrostideae.
Connor, H. E. 1963: Breeding systems in New Zealand grasses. IV. Gynodioecism in Cortaderia. N.Z. J. Bot. 1: 258-264.
Connor, H. E. 1965: Breeding systems in New Zealand grasses. V. Naturalised species of Cortaderia. N.Z. J. Bot. 3: 17-23.
Connor, H. E. 1965: Breeding systems in New Zealand grasses. VI. Control of gynodioecism in Cortaderia richardii. N.Z. J. Bot. 3: 233-242.
Connor, H. E. 1965: Breeding systems in New Zealand grasses. VII. Periodic flowering of snow tussock Chionochloa rigida. N.Z. J. Bot. 4: 392-397.
Connor, H. E. 1973: Breeding systems in Cortaderia (Gramineae). Evolution 27: 663-678.
Connor, H. E. and B. A. Matthews. 1977: Breeding systems in New Zealand grasses. VIII. Cleistogamy in Microlaena. N.Z. J. Bot. 15: 531-534.
Connor, H. E. 1979: Breeding systems in the grasses: a survey. N.Z. J. Bot. 17: 547-574.
Connor, H. E. 1981: Evolution of reproductive systems in the Gramineae. Ann. Miss. Bot. Gard. 68: 48-74.
Connor, H. E. 1984: Breeding systems in New Zealand grasses. XI. Sex ratios in dioecious Spinifex sericeus. N.Z. J. Bot. 22: 569-574.
Connor, H. E. 1987: Reproductive biology in the grasses. In Soderstrom, T. R. et al. (Eds) Grass Systematics and Evolution. Washington, D. C., Smithsonian Institution Press, pp. 117-132.
Connor, H. E. 1988: Breeding systems in New Zealand grasses. X. Species at risk for conservation. N.Z. J. Bot. 26: 163-167.
Connor, H. and D. Charlesworth. 1989: Genetics of male sterility in gynodioecious Cortaderia (Gramineae). Heredity 63: 373-382.
Connor, H. E. 1990: Breeding systems in New Zealand grasses. XI. Gynodioecism in Chionochloa bromoides. N.Z. J. Bot. 28: 59-65.
Connor, H. E. 1998: Breeding systems in New Zealand grasses. XII. Cleistogamy in Festuca. N.Z. J. Bot. 36: 471-476.
McKone, M. J., Thom, A. L. and D. Kelly. 1997: Self-compatibility in Chionochloa pallens and C. macra (Poaceae) confirmed by hand pollination of excised styles. N.Z. J. Bot. 35: 259-262.
