Intersubgeneric hybridization of soybeans with a wild perennial species,Glycine clandestina Wendl

Summary The exploitation of wild perennial species of subgenus Glycine has been formidable in soybean breeding programs because of extremely poor crossability and an early pod abortion. The combination of gibberellic acid application to hybridized gynoecia and improved seed culture media formulations resulted in a new intersubgeneric hybrid between Glycine max (L.) Merr. (2n=40) and G. clandestina Wendt. (2n=40). Of the 31 immature seeds cultured, 1 regenerated 21 plants through organogenesis while the remaining 30 failed to germinate. All the regenerated plants were similar morphologically, carried expected 2n=40, possessed hybrid isozyme patterns and were completely sterile. Complete absence of chromosome pairing was observed in 40.9% sporocytes. The occurrence of 1 to 6 loosely paired rod bivalents suggests some possibilities of allosyndetic pairing. Hybrid plants set aborted pods after backcrossing to G. max.     

Genetic variation of trypsin and chymotrypsin inhibitors in pigeonpea [Cajanus cajan (L.) Millsp.] and its wild relatives

Variation in the trypsin inhibitors (TIs) and the chymotrypsin inhibitors (CIs) among 69 pigeonpea [Cajanus cajan (L.) Millsp.] strains from a wide geographical distribution and among 17 accessions representing seven wild Cajanus species was studied by electrophoretic banding pattern comparisons and by spectrophotometric activity assays. The TI and CI electrophoretic migration patterns among the pigeonpea strains were highly uniform but varied in the inhibitor band intensities. The migration patterns of the inhibitors in the wild Cajanus species were highly species specific. The mean TI activity of pigeonpea strains (2279 units) was significantly higher than that of the wild Cajanus species (1407 units). However, the mean CI activity in the pigeonpea strains (62 units) was much lower than that in the wild species (162 units). Kenya 2 and ICP 9151 were the lowest and the highest, respectively, in both the TI and CI activities among all the pigeonpea strains used in this study. A highly-significant positive correlation was observed between the TI and CI activities. The Bowman-Birk type inhibitors with both TI and CI activities were identified in all the pigeonpea strains and also in the accessions of all the wild species except C. volubilis (Blanco) Blanco. The C. volubilis accession ICPW 169 was found to be null for both CI bands and CI activity. Environment, strain, and environment x strain interaction showed highly-significant effects on both the TI and CI activities. Growing the pigeonpea strains at a different environment from their area of adaptation increased TI and CI activities and also altered the maturity period.     

Genomic relationships in the genus Glycine (Fabaceae: Phaseoleae): use of a monoclonal antibody to the soybean Bowman-Blrk inhibitor as a genome marker

We investigated the use of a monoclonal antibody (MAb 238) to the soybean Bowman-Birk inhibitor (BBI) to verify and understand the intergenomic relationships among the wild perennial Glycine species. Competitive enzyme linked immunosorbent assay and western blot screening studies revealed that the accessions of B-genome (G. latifolia, G. microphylla, and G. tabacina, 2n = 40) and C-genome (G. curvata and G. cyrtoloba) species did not contain the MAb 238 crossreactive proteins (BBI-nulls). By contrast, all the A-genome (G. argyrea, G. canescens, G. clandestina, and G. latrobeana), E-genome (G. tomentella, 2n = 38), and F-genome (G. falcata) species, G. arenaria (genome unknown), and the polyploid (2n = 78,80) G. tomentella accessions were BBI-positive. The D-genome G. tomentella (2n = 40) and tetraploid G. tabacina (2n = 80) contained both BBI-null and BBI-positive type accessions. Among the recently described species, G. hirticaulis (2n = 40), G. lactovirens, and G. pindanica contained the MAb 238 crossreactive proteins while G. albicans did not. Glycine hirticaulis, G. pindanica, and G. tomentella (2n = 38) displayed highly similar MAb 238 crossreactive isoelectric focusing banding patterns, indicating that they are genomically close to each other. Glycine hirticaulis was found to have both diploid (2n = 40) and tetraploid (2n = 80) cytotypes. We demonstrated that the MAb 238 was specific to the trypsin inhibitor domain of the BBI. The MAb 238 clearly reflected all the previously established relationships in the genus Glycine, validating its use as a genome marker.     

Synthesis of benzene ruthenium triazolato complexes by [3+2] cycloaddition reactions of activated alkynes and fumaronitrile to benzene ruthenium azido complexes

The dinuclear complex [(η⁶-C₆H₆)Ru(μ-N₃)Cl]₂ (1) is obtained by the reaction of [(η⁶-C₆H₆)RuCl₂]₂ with sodium azide in ethanol. The benzene ruthenium β-diketonato complexes of the general formula [(η⁶-C₆H₆)Ru(L∩L)Cl] {L∩L = O,O′-acac (2); O,O′-bzac (3); O,O′-dbzm (4)} are obtained in methanol by the reaction of [(η⁶-C₆H₆)RuCl₂]₂ with the corresponding β-diketonates. These complexes further react with sodium azide in ethanol to yield complexes of the type [(η⁶-C₆H₆)Ru(L∩L)N₃] [L∩L = O,O′-acac (5); L∩L = O,O′-bzac (6); L∩L = O,O′-dbzm (7)]. The complexes 5-7 are obtained as well by treating 1 with sodium salts of β-diketonates. These neutral benzene ruthenium azido complexes undergo [3+2] dipolar cycloaddition reaction with activated alkynes (MeO₂CCCCO₂Me, EtO₂CCCCO₂Et) or fumaronitrile (NCHCCHCN) to yield the corresponding benzene ruthenium triazolato complexes; [(η⁶-C₆H₆)Ru(O,O′-acac){N₃C₂(CO₂Me)₂}] (8), [(η⁶-C₆H₆)Ru(O,O′-acac){N₃C₂(CO₂Et)₂}] (9), [(η⁶-C₆H₆)Ru(O,O′-acac){N₃C₂HCN}] (10), [(η⁶-C₆H₆)Ru(O,O′-bzac){N₃C₂HCN}] (11) and [(η⁶-C₆H₆)Ru(O,O′-dbzm){N₃C₂HCN}] (12). These complexes are fully characterized on the basis of microanalyses, FT-IR and FT-NMR spectroscopy. The molecular structure of [(η⁶-C₆H₆)Ru(O,O′- acac){N₃C₂(CO₂C₂H₅)₂}] (9) is confirmed by single crystal X-ray diffraction study.     

Correlation between the inhibition of photosynthesis and the decrease in area of detached leaf discs or volume/absorbance of protoplasts under osmotic stress in pea (Pisum sativum)

Exposure to osmotic stress reduces leaf area and protoplast volume while decreasing photosynthesis. But the measurement of protoplast volume is tedious, while rapid determinations of leaf area in the field are difficult. We evaluated the quantitative relationship between the extent of decrease in area of detached leaf discs or the volume of protoplast of pea ( Pisum sativum ) and reduction in their photosynthetic capacity under osmotic stress. Osmotic stress was induced by increasing sorbitol concentration in the surrounding medium of the leaf discs from zero to 1.0 M (-3.1 MPa), and in case of protoplasts from 0.4 M (-1.3 MPa, isotonicity) to 1.0 M (-3.1 MPa, hypertonicity). There was a high degree of positive correlation between the extent of reduction in the area of detached leaf discs or the volume of protoplasts (indicated by diameter or absorption at 440 nm) and the decrease in photosynthesis. The correlation coefficients between inhibition of photosynthesis and the decrease in leaf disc area or protoplast volume were 0.96 and 0.99, respectively. We therefore suggest that the decrease in absorbance at 440 nm (corrected for turbidity at 750 nm) can be used as a simple measure to predict the inhibition due to osmotic stress of photosynthesis in mesophyll protoplasts. Similarly, the reduction in area of detached leaf discs could also be a very simple and useful criterion to assess osmotic tolerance of photosynthesis.     

Genomic relationships among diploid wild perennial species of the genus Glycine Willd. subgenus Glycine revealed by crossability,meiotic chromosome pairing and seed protein electrophoresis

Summary The nomenclature of species beased on classical taxonomy can be verified from cytogenetic, biochemical and molecular studies. The objective of the study presented here was to provide further information on genomic affinities among species of the genus Glycine Willd. based on crossability, meiotic chromosome pairing of F₁ hybrids and seed-protein profiles. Meiotic chromosome pairing data revealed no genomic similarity between G. microphylla (BB) and G. falcata (FF), nor between G. tomentella (2n = 38; EE) and G. microphylla (BB). Despite morphological similarity between G. cyrtoloba (CC) and G. curvata no F₁ hybrid was obtained, although 748 flowers were pollinated. The seed-protein banding patterns showed G. latrobeana to be closer to the A-genome species than to others. Based on these results we assign genome symbol A₃A₃ to G. latrobeana. Likewise, G. curvata was allotted the designation C₁C₁ because the seed-protein banding patterns of G. curvata and G. cyrtoloba are similar. The genome designations of Glycine species based on cytogenetic investigations may be further extended by results obtained from biochemical and molecular approaches.Research supported in part by the Illinois Agricultural Experiment Station and US Department of Agriculture Competitive Research Grant 88-37231-4100