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- Author or Editor: George C. Martin x
- HortScience x
Abstract
Historians tend to find what they are looking for. My bias in developing historical aspects of Growth Regulators (GR) in Pomology has been positive, as I believe that control of plant growth will eventually be possible. The thought processes and actions taken by individuals who led the way to eventual use of GR are difficult to access. Perhaps the beginnings were initiated by those who had the time to observe plant growth and write down what they saw. To credit any one individual would be of doubtful accuracy. Historically, the one who accumulates fame for a breakthrough put the finishing touches on an idea which had evolved over a long period of time.
Abstract
None of the physiological events in plant growth and development is truly independent. Photosynthesis, flowering, and mineral transport are sharply focused areas of research; yet these phenomena are not separable from other metabolic events in the plant. This feature of interdependence may be called correlations (26) or growth correlations (49, 50). The control exerted by the growth zone emanates from a meristem; these meristems include the root or shoot apex, cambium, flowers, fruit, pollen on stigma, and the ovule or seed in a fruit.
Abstract
‘Tan-ginbozu’ dwarf rice was responsive to root-applied gibberellins which had previously been separated by thin layer chromatography on glass fiber sheets. A 3-day test was less variable than 4, 5, 6 or 7-day tests. Seven replications enabled 50% differences in growth to be discernible with 95% confidence among 3 treatments; with 2 treatments, 50% differences in growth were discernible with 4 replications.
Abstract
Flowers of caged ‘Winter Nelis’ pear (Pyrus communis L.) set parthenocarpic fruit that persisted until maturity after a single treatment with the gibberellin GA3, GA3 + CaCl2 or the pear gibberellin GA45. Cytex (a zeatin-like cytokinin), abscisic acid (ABA), GA9, GA17 and GA25 were ineffective. The persisting fruits treated with GA3 or GA3 + CaCl2 were significantly smaller than the controls and the GA3 + CaCl2 treated fruits were significantly smaller than those treated with GA45.
Abstract
In the paper “Determination of moisture in walnut seeds by near-infrared spectrophotometry” by Robert C. Campbell and George C. Martin, (HortScience 11(5):494. 1976), two errors on page 495 have been noted.
Abstract
Analysis for hormones in plant material received impetus from the early studies of Went (4). Since that time, scientists have used living plant materials to estimate the presence of specific hormones. Among the advantages of the bioassay are sensitivity to the nanogram and in some cases, picogram range, ease of use, functionality with high levels of contaminants, and low cost of operation. The disadvantages include lack of specificity, variable response, and, in most instances, the need to use a species foreign to the one under examination.
Xenia and metaxenia are phenomena dealing with the effects that pollen from different sources have on certain characteristics exhibited by seeds and fruits in a variety of species. A review of dictionaries, textbooks, and the scientific literature reveals that there is widespread confusion with regard to the nature of these phenomena and how they are to be distinguished. This discussion will attempt to clarify the boundary between these related phenomena by examining both the origins of the terms and our present understanding of the metabolism and anatomy involved. From this perspective, we contend that xenia applies to pollen effects as exhibited in the syngamous parts of ovules, that is, the embryo and endosperm only. Metaxenia applies to such effects found in any structure beyond the embryo and endosperm, this is, in tissues which derive wholly from mother plant material. Metaxenia then encompasses effects found in seed parts such as the nucellus and testa as well as those found in carpels and accessory tissue.
Xenia and metaxenia are phenomena dealing with the effects that pollen from different sources have on certain characteristics exhibited by seeds and fruits in a variety of species. A review of dictionaries, textbooks, and the scientific literature reveals that there is widespread confusion with regard to the nature of these phenomena and how they are to be distinguished. This discussion will attempt to clarify the boundary between these related phenomena by examining both the origins of the terms and our present understanding of the metabolism and anatomy involved. From this perspective, we contend that xenia applies to pollen effects as exhibited in the syngamous parts of ovules, that is, the embryo and endosperm only. Metaxenia applies to such effects found in any structure beyond the embryo and endosperm, this is, in tissues which derive wholly from mother plant material. Metaxenia then encompasses effects found in seed parts such as the nucellus and testa as well as those found in carpels and accessory tissue.
Foliar sprays of TIBA inhibited the growth of apple seedlings, and induced bitter pit of field grown `Golden Delicious' fruit. Total Ca levels were significantly decreased in the stems and leaves of apple seedlings, and in fruit peel. Foliar sprays of NAA increased total Ca content in shoots of apple seedlings. The Ca levels in the roots of seedlings were affected less by TIBA and/or NAA sprays than that of shoots. Irrigation after TIBA treatment inhibited apple seedling growth, and decreased total Ca content in shoots and roots, while NAA increased the growth and Ca content in the seedlings. TIBA via lanolin mixture to the shoot inhibited growth, and decreased the Ca content in shoots and roots of apple seedlings. NAA via lanolin mixture did not affect growth, whereas it increased the Ca content in the shoots of apple seedlings.