ANALYSIS OF INTROGRESSIVE LINES OF INTER-SPECIES PEA HYBRIDS BY BAND COMPOSITION OF SEED PROTEINS

Background. The reproductive incompatibility of cultivated (Pisum sativum) and wild (P. fulvum) pea species determines the difficulties of obtaining hybrids as well as the transfer of valuable wild parent alleles into interspecific hybrids and their use in the breeding process. The aim of the research was a comparative study of protein spectra of pea interspecific hybrids BC2F5 P. sativum x P. fulvum obtained by the authors and their parents. Materials and methods. The band composition of seed proteins in the interspecific hybrids of peas BC2F5, variety Stabil (P. sativum) accession from VIR collection I-609881 (P. fulvum) has been studied. Effectiveness of parent gene transfer determining each polymorphic position of electrophoretic spectrum were evaluated. Results. The ratio of the actual frequencies of the bands of the cultivated and wild parents in the introgression lines corresponded to the expected level in 73% of the positions of the electrophoretic spectrum. The introgression rate of individual seed protein bands from wild parent into interspecific pea hybrids in the absence of selection significantly exceeded the expected level, which may indicate the adaptive value of alleles encoding unique seed protein isoforms. Conclusion. The possibility of introgressive transfer of wild-type alleles to the cultivated genotypes of pea, as well as the presence of identified cultivated isoforms of storage proteins in all studied lines of BC2F5 interspecific hybrids in 88.2% of the polymorphic positions of the electrophoretic spectrum, indicates the possibility of using the wild species P. fulvum in pea breeding.

Musa × parahaekkinenii (Musaceae): A new artificial interspecific hybrid from Kerala, India

Musa × parahaekkinenii (Musaceae), a new manually crossed interspecific hybrid of two wild parent plants Musa coccinea Andrews (female) and Musa haekkinenii N.S. Lý & Haev. (male), is described and illustrated. A comparison of characters with its parents and a key to the new hybrid M. × parahaekkinenii are provided.

Lutein esterification in wheat endosperm is controlled by the homoeologous group 7, and is increased by the simultaneous presence of chromosomes 7D and 7Hch from Hordeum chilense

The high carotenoid content in tritordeum (×Tritordeum Ascherson et Graebner) grains is derived from its wild parent, Hordeum chilense Roem. et Schulz. Phytoene synthase 1 (Psy1) is located on chromosome 7HchS and plays a major role in this trait. This study investigates the impact of the introgression of chromosome 7Hch into common wheat background on carotenoid composition, including xanthophylls esterified with fatty acids (monoesters and diesters). All of the genetic stocks carrying Psy1 from H. chilense increased their carotenoid content relative to common wheat. In addition, significant changes in the carotenoid profile were detected in different genetic stocks. The most relevant was the increase in content of lutein diesters when both 7Hch and 7D were present, which indicates the existence of genes involved in the esterification of xanthophylls in both chromosomes. Furthermore, our results suggest that 7Hch genes preferentially esterify lutein with palmitic acid, whereas 7D is either indifferent to the fatty acid or it prefers linoleic acid for lutein esterification. The involvement and complementarity of 7Hch and 7D are highly significant considering the scarcity of previous results on lutein esterification in wheat.

SALT TOLERANCE OF A SELECTED LINE FROM THE CROSS BETWEEN A WILD, TOLERANT TOMATO SPECIES (LYCOPERSICON CHEESMANII, ECOTYPE LA 1401) AND A CULTIVATED SPECIES (L. ESCULENTUM MILL.)

A salt-tolerance selected F5 generation from a cross between the wild tomato species, Lycopersicon cheesmanii, ecotype LA 1401, and the cultivated species, L. esculentum Mill. (cv Heinz 1350) was compared to the wild parental line in a solution culture experiment to determine the effects of selection on salt tolerance, and ion discrimination and accumulation characteristics in the selected line. Seedlings were transplanted to nutrient solutions at the 3 to 4-leaf stage of growth and after a 1-week period of adjustment, were salinized at 25 mM NaCl day-1 (approximately -1 bar osmotic potential) to final salt concentrations of 0, 50, and 100 mM. Plasmalemma and tonoplast vesicles were isolated from fresh root samples, and ATPase and Na+/H+ antiport activity was determined using fluorescence assays. The selected line restricted Na uptake into the shoot and maintained higher shoot K+ than did the wild parent. Growth rate under salinity was greater in the selected line than in the wild species, but relative salt tolerance was higher in the wild parent. Interspecific hybridization appears to be a useful process for the transfer of salt tolerance characters from wild to cultivated tomato.

RECESSIVE MUTATIONS FROM NATURAL POPULATIONS OF NEUROSPORA CRASSA THAT ARE EXPRESSED IN THE SEXUAL DIPLOPHASE

ABSTRACT Wild-collected isolates of Neurospora crassa Shear and Dodge were systematically examined for recessive mutations affecting the sexual phase of the life cycle, which is essentially diploid. Seventy-four of 99 wild-collected isolates from 26 populations in the United States, India and Pakistan carried one or more recessive mutations that reduced fertility significantly when homozygous; mutations affecting spore morphology were also detected. Limited complementation tests indicate that most of the 106 recovered mutations are unique.—The recessive diplophase (= sexual phase) mutations were uncovered by crossing each wild-collected isolate to a marked two-chromosome double-reciprocal translocation strain as "balancer." Surviving progeny receive approximately 60% of their genome from the wild parent, but receive the mating-type allele from the "balancer" parent. These progeny were backcrossed to the wild parent and were also crossed with a standard laboratory strain (fl). Reduced fertility in the backcross vs. normal fertility in the cross with the laboratory standard signals the presence of a recessive mutation in the wild-collected isolate.—Most of the mutants (95 of 106) fall into two major classes: those producing barren perithecia with no or few viable ascospores (51) and those with spore maturation defects (44). Most of the recessive barrens result either from an early block in meiosis or ascus development (25) or from a late disturbance in postmeiotic ascus behavior (18).—These recessive mutations are formally equivalent to recessive lethals in higher eukaryotes and may be important in determining the breeding structure of natural Neurospora populations.

SOLUBILISATION D'ENZYMES HYDROLYTIQUES CHEZ GOSSYPIUM HIRSUTUM, G. ANOMALUM ET DES DERIVES DE L'HYBRIDATION ENTRE CES DEUX ESPECES

Hybrid derivatives between Gossypium anomalum and G. hirsutum, both 2n + 1 aneuploids for chromosome 3 of G. anomalum and euploids derived from this segregating population, exhibit under osmotic stress conditions the same pattern of solubilization of the hydrolytic enzymes, β-fructofuranosidase, β-amylase and acid phosphatase, as the wild parent G. anomalum.This biochemical relationship and the slightly changed phenotype, suggest that the hereditary material could have been transferred from G. anomalum to the euploids.