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Contributed Papers ALLEN, RANDY D.*, DAVID A. PRIER AND LOUIS H. BRAGG. Department of Biology, Texas A&M University, College Station, TX 77843 and Department of Biology, University of Texas at Arlington, Arlington, TX 76019. -Ultrastructure of Prosopis glandulosa cotyledon cells during storage mobilization. Cotyledon cells of Prosopis contain numerous large protein bodies which are closely surrounded by a single layer of minute lipid bodies. Lipid bodies also line the inner face of the plasmalemma. After germination, the protein body matrix first develops a granular appearance. Later, electron transparent regions form, usually at the protein body periphery. These areas are memibrane botnd and have been termed "Protein body vacuoles." These areas swell and may become much larger than the original protein bodies. Electron dense protein body fragments remain within the protein body vacuoles. Fusion of protein body vacuole areas eventually results in the formation of a large main cell vacuole which still contains spherical fragments of undigested storage protein. Lipid bodies enlarge slightly but retain their position around protein bodies until enlargement of the protein body vacuole. Some evidence of lipid body fusion is seen and fewer, larger lipid bodies are observed in cells at later stages of development. ALMOUSAWI, A.H., P.E. RICHARDSON,* R.L. BURTON. Department of Entomology and Botany, Oklahoma State University, Stillwater, OK 74078 - The Ultrastruc- ture of Greenbug Feeding Damage in Susceptible and Resistant Wheat Cultivars. Cell and tissue differences resulted when biotype C greenbugs Schizaphis graminum (Rondani) fed on susceptible as opposed to resistant wheat cultivars. There were two different types of cell damage in the susceptible cultivar (TAM W-101). Adjacent to aphid feeding tracks in vascular bundles there was extensive and rapid damage to a few phloem cells and their contents. In a second type of damaged area there was slower degeneration of organelles of mesophyll parenchyma cells in areas traversed by the tracks. Chloroplasts lost all membrane structure. Later, vesicles appeared in mitochondrial cristae and in the nuclear envelope. Dense sheath material was located in many feeding sites. Resistant wheat (Amigo x TAM W-101) was symptomless at 10 days post- infestation. At two days there were a few patches of scattered collapsed dried mesophyll cells surrounded by many unaffected cells. Salavary sheath material was found at 2 days post-infestation but not later. Feeding tracks in susceptible wheat are mostly intercellular with feeding in the phloem. Feeding damage to the resistant variety was mainly to mesophyll, was slight, and appeared to result in little persistant damage. There were no physical structural differences between varieties, and differences in extent and types of feeding tracks and damaged cells appeared to reflect genetic, physiological, and biochemical differences. ANDERSON, LORAN C. Department of Biological Science, Florida State University, Tallahassee, FL 32306.--Neotenic expression in Gordonia stomata. The Loblolly Bay, G. lasianthus (Theaceae), is a medium-sized evergeen tree. Large buttressed peristomatal rims characterize the stomata. Extensive Developmental and Structural Section 15 survey for stomatal variation throughout the species ' range found that a few trees had a strikingly different cuticular pattern around the stomata (concentric rings of striae rather than buttressed cups). Seeds were germinated from plants having the standard buttressed cup cuticles. Stomata of cotyledons lack cuticular relief; seedling leaves are sequentially more elaborate in cuticular build-up until eventually they achieve the striate pattern seen rarely on older (neotenous) trees. Root sprouts, on mature "standard pattern" trees, have the juvenile cuticular pattern as well. The general tree age for switching to cuticles with buttressed peristomatal cups has not been determined. ARMSTRONG, JOSEPH E. Department of Biological Sciences, Illinois State University, Normal, IL 61761. - The comparative floral anatomy of the Solanaceae. There have been relatively few studies of floral anatomy in the Solanaceae and none of the broad, comprehensive studies necessary for comparative study of the systematics and phylogeny of this family. A preliminary survey of floral anatomy in the Solanaceae was recently undertaken to provide a basis for further studies. The vascular anatomy and histology of the floral organs provided numerous characters and character states of potential systematic usefulness. Preliminary observations support the recognition of two subfamilies, Solanoideae and Cestroideae, and also supports their proposed relative level of phylogenetic specialization. Anatomical characters support the recognition of the endemic Australian genera as the tribe Anthocercideae. The Lycieae and Nicotianeae are similarly distinct tribes based on anatomical characters. Floral anatomy does not support the recognition of the Nolanaceae as a separate family. ARNOTT, HOWARD 3.* and MARY ALICE WEBB. Department of Biology, The University of Texas at Arlington, Arlington, TX 76019-0498. - Calcium oxalate crystal development in a fungus found in pine beetle mines in the cambial zone of Pinus ponderosa The production of calcium oxalate crystals by fungal hyphae has been established for almost a century (De Bary, 1887), but up to now only a few examples have been studied with electron microscopy. In the present case we have studied a fungus found growing in association with a pine beetle that bored through the cambial region of Pinus ponderosa logs collected in Pagosa Springs, Colorado. The fungus produces clamp connections and is therefore a basidiomycete, but is otherwise not yet identified. The fungus produces a white mat in the beetle mines, both in association with the bark and the beetle excrement. In many areas the white mat is many hyphal layers thick. Calcium oxalate dihydrate (Weddellite) is produced by the hyphae in three ways. 1) Single bipyramidal crystals develop along the surface of the hyphae. 2) An encrusta- tion of many small interpenetrant twins is produced along segments of hyphae. 3) Druse-like multiple interpenetrant twins are also found. Many of these druse-like bodies are produced as terminations of main hyphae or terminations of short lateral hyphal branches. Occa- sionally the druse-like bodies are produced on one side of a hypha similar to those reported by Arnott (1983). TEM and SEM observations on the development of these three forms of calcification will be presented and discussed. De Bary, A. 1887. Comparative Morphology and Biology of Fungi, Mycetozoa and Bacteria. Clarendon Press, Oxford; Arnott, H. J. Calcium oxalate (Weddellite) crystals in forest litter. Scanning Elect. Microsc., 1983. III: 1141- 1149.
16 Developmental and Structural Section BARKER, W. GEORGE. Department of Botany and Genetics, University of Guelph, Guelph, ON NlG 2W1. - Further observations on the regenerative pattern of Impatiens balsamini L. seedlings following mutilations. In continued studies on regenerative behaviour of seedlings of Impatiens balsamini L., garden balsam, additional patterns have been identified. The seeds now available exhibit after germination the same developmental sequences as those discussed (Annals of Botany 47:661, 1981) but the events occur more rapidly than reported. Additionally, a series of further experiments discloses other behaviours of this plant following seedling mutilations. The ability to form a regenerated collet is minimized and lost as the seedling ages. The tendency to form roots in the area basipetal to the excised collet persists as seedlings mature but without the encircling collet swelling and without associated hairs. Single roots become more common than the four earlier noted. In seedlings of ca. 6.0 cm in total length the rooting after mutilation is quite distinctive if the excising cut is made immediately behind the collet, midway between collet and cotyledon and adjacent to cotyledons. It is quite apparent that the control leading to the regeneration of the collet-root complex is diminished with physiological age. BARKER,* W. GEORGE, and HUSSEY, D. BLAINE. Department of Botany and Genetics, University of Guelph, Guelph, ON NlG 2W1. - The initiation of lateral root primordia during the early development of seeds in Impatiens balsamina L. Impatiens balsamina L. seedlings produce a swollen encircling ring, the collet basipetal to the root apical meristem. From this four lateral roots emerge promptly after germination. As recently reported (Annals of Botany 47-661, 1951), mutilation of seedling by excision of the collet-radical-lateral root apparatus will result in the regeneration of a basal encircling swelling from which four lateral roots and root hairs will emerge (regenerated collet). Present evidence suggests that this regeneration requires the presence of cotyledonary tissue. It was considered central to further work on lateral root development in garden balsam to establish the normal pattern of development of the collet-lateral root complex. To this end plants were grown in the greenhouse and sections were made of developmental stages subsequent to fertilization and including the visual appearance of the collet subsequent to germination. It is apparent that the essence of the collet complex was present very early in the development of the embryo. BENDA, G. T. A. U.S. Sugarcane Field Laboratory, Box 470, Houma, LA 70361. -Leaf-base overlap in subtending leaves and bud scales of a sugarcane clone. The sequence of direction of overlap of leaf bases was determined for groups of four leaves, each group consisting of the subtending leaf and the three oldest scale leaves of the main bud in its axil. A total of 380 nodes was examined from 10 greenhouse- grown shoots, 15 to 18 months of age, of a sugarcane clone (Saccharum interspecific hybrid, CP 68-413) selected because of the frequent occurrence of one or two supernumerary buds per node. The sequence was identified unequivocally for 244 groups. The subtending leaves (lv) had 120 of an expected 122 leaf bases which overlapped to the left, the oldest scale leaves (sl), 117, the second-oldest scale leaves (s2), 112, and the third-oldest scale leaves (s3), 132. The direction of overlap was the same for lv and sl in 65% of the groups, for s1 and S2 in 56%, and for s2 and s3 in 39%. When the groups were classified according to the sequence of direction of overlap from lv to s3, all classes corresponding to the 16 permutations had some groups, but the distribution among classes was not uniform. When these classes were assigned to five combina- tions, the number of groups in each were as follows: all left (14), three left-one right (61), two left- two right (89), one left-three right (64), all right (16). These results agree with those p'redicted from the binomial formula for equal probability of overlap in either direction. When the direction of overlap of s1 was compared for the main.and supernumerary bud of 98 two-budded nodes, the results showed that it was the same for 50 and opposite for 48 pairs. These results demonstrate that the sequence of direction of overlap in this clone does not follow a standard pattern of development such as a sequential alternation of direction. BRAGG, LOUIS H. Biology Department, University of Texas at Arlington, Arlington, TX 76019. - The testa, hilum, and tracheoids of selected Lupinus seeds. Seeds of Lupinus texensis Hook., L. subcarnosus Hook., and L. havardii S. Wats. were examined with scanning electron microscopy for characters that would separate them at the species level. Varia- tions of the basic simple-foveolate pattern of the testa were distinctively different for each species with minor exceptions. This basic pattern has been unreported for the genus. The hila shapes are species characteristic as well. The tracheid bar is the most common type found in the subfamiLy but possesses tracheoid variations between these species. Usefulness of the testa and the hilum as taxonomic characters is suggested. BROWN, ROY C. and BETTY E. LEMMON. Department of Biology, University of Southwestern Louisiana, Lafayette, LA 70504 - Microtubule organization and morphogenesis in young spores of the' moss Tetraphis pellucida Hedw. Microtubule systems appear sequentially at the distal and proximal poles of tetrad members during mid- sporogenesis in the moss Tetraphis pellucida Hedw. The distal microtubule system, which'appears immediately after cytokinesis, emanates from a microtubule organizing center (MTOC) located between the single plastid and the nucleus. Whereas the distal system is ephemeral, the proximal microtubule system, which appears slightly later than the distal system, is a more stable component of mid-sporogenesis. The proximal MTOC is an irregularly lobed, patelliform aggre- gation of electron-dense granules located beneath the plasma membrane at the proximal spore pole. Several bundles of microtubules radiate from the proximal MTOC and traverse the cell, enclosing the nucleus in a cone of microtubules. The proximal microtubule system is thought to function in aperture development and organelle migration. The nucleus migrates to the proximal pole early in the tetrad stage and maintains
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