Natural Hybridization Among Four Species of Baptisia (Leguminosae)

Abstract

Alston, R. E., and B. L. Turner. (U. Texas, Austin.) Natural hybridization among four species of Baptisia (Leguminosae). Amer. Jour. Bot. 50(2): 159–173. Illus. 1963.— Interspecific hybridization involving 4 species of Baptisia (B. leucophaea, B. sphaerocarpa, B. nuttalliana, and B. leucantha) has been studied by means of extensive field work and subsequent morphological and chromatographic analyses. As a result of these studies, numerous hybridizing populations involving any 2, 3 and, in 1 instance, 4 species have been located. Near Dayton, Texas, all 4 species and all 6 of the possible 2‐way hybrid combinations have been found in a single field. Approximately 125 different chemical compounds have now been detected in the 4 species. Many of these compounds serve as species specific markers useful in the validation of specific hybrid types. Hybrids between B. leucophaea and B. sphaerocarpa and between B. leucophaea and B. nuttalliana are numerous, and in these large hybrid swarms a chromatographic and morphological analysis of population structure is possible. The former combination provides an excellent opportunity for the utilization of chemical markers as criteria for introgressive hybridization. The hybrid B. leucantha × B. sphaerocarpa is frequently encountered and contains a large number of compounds species‐specific for one or the other parental species. The other 3 hybrid types have been found infrequently. Certain hybrid types are generally similar morphologically (e.g., B. leucantha × B. sphaerocarpa as opposed to B. leucantha × B. nuttalliana), and chromatographic techniques are of great value in the absolute identification of such plants, especially in complex populations where backcrossing further complicates the interpretation of the background of a plant from exomorphic features alone.

SEED POLYMORPHISM AND GERMINATION II. THE ROLE OF HYBRIDIZATION IN THE GERMINATION POLYMORPHISM OF RUMEX CRISPUS AND R. OBTUSIFOLIUS

“…(3) 7-5 (12) (0-8) 2-2 (4-6) (40) 80 (130) (40) (2) 4-4 (7) 4-2 (60) 92 (130) (40) 74(110) (3) 9-6 (30) 0 0 (rare) 0 (rare) (II) 14-5 (18) (210) (40) 64 (100) (3) 8-9 (20) ft-present present present (9) 14-6(17) (60) 64 (70) ( 0-6) 0-8 (1-6) (5) 9-9 (20) (0^9) 2-1 (3-6) (40) 78 (140) (30) 40 (50) (0-7) 1-2 (2-0) 0-present present present (11) 14-7(21) acetic acid-water for 11 h and for 2 h in 15% v/v acetic acid. Chromatograms were examined under UV light and UV light and ammonia (Alston & Turner, 1963). Germination ofseeds of selected plants from one population (Packington) was tested using alternating temperatures (1O-25''C) in darkness.…”

Morphological and Physiological Differentiation of Phoradendron Populations in Texas

“…By the criteria of Anderson (1939Anderson ( , 1949, the patterns of intergradation and mixing of morphology, flavonoids, and freeze tolerance between the northern and southern types suggest that introgressive hybridization has occurred. Mixing of morphological characteristics and flavonoid patterns has been used extensively in the study of hybridization between Baptisia species (Alston and Turner, 1963). Mixing of morphological characteristics and associated quantitative differences in flavonoid patterns also have indicated possible introgression between Tragopogon species (Brehm and Ownbey, 1965).…”

The “Potentilla collina problem”- a chemotaxonomic approach

“…Among the many studies on plant phenolics may be mentioned the extensive work on Baptisia (ALSTON andTURNER 1962, 1963;ALSTON, MABRY and TURNER 1963;ALSTON 1965) and on the Lemnaceae (MCCLURE and ALSTON 1966). The Baptisia studies clearly show the value of chemotaxonomical methods in the study of complex natural hybridization and especially introgression.…”