Cytological and genetical studies of a male sterile celery

Summary The inheritance and nature fo male sterility of a cerley (Apium graveolens L.) strain (MS1) is reported. Male sterility in MS1 is determined by a a recessive genotype for a single locus. Tests for linkage with the isozyme chromosome markers SDH-1 and PGM-1 were negative. MS1 male sterility was associated with a defective tapetum characterized by prominent vacuoles and premature degeneration. The stamens in the male sterile strain persisted in the flowers up to stigma receptivity, while in the male fertile plants they dropped before style expansion. The male sterile flowers produced normal amounts of nectar, resulting in cross pollination by various species of pollinators. It was estimated that the sterile strain produced 30% less seed than normal male fertile. Its possible use for hybrid celery seed production is discussed.Research supported by grants from the California Celery Research Board and BARD I-483-82.     

Characterization of graft-induced change in capsaicin content of Capsicum annuum L.

Summary Capsaicin contents were measured in the progenies from the test crosses between the strain, G₅S₁₇ derived from fruit with the graft-induced change in fruit shape and the original two cultivars, Yatsubusa (Capsicum annuum L. var fasciculatum Ilish) and Spanish Paprika (C. annuum L. var. grossum Sendt) used for grafting.The strain, G₅S₁₇ contained a lower amount of capsaicin than the original pungent cultivar Yatsubusa used as scion. The characteristic of the lowered capsaicin content in the strain has been stably inherited through seed propagation, and has also been transmitted to the progenies from the crosses with the original two cultivars used for scion or stock. These features in the capsaicin content agreed with those in fruit shape in the graft-induced change.     

Somaclonal variation in three Argentinean varieties of Triticum aestivum with different karyotypic instability*

Three cultivars of wheat showing different levels of spontaneous karyotypic instability were studied regarding their stability in vitro for a number of characters, i.e. chromosome structure, gliadin pattern, glume and grain colour, awn type, chlorophyll pigmentation and plant morphology. The progenies of somaclones derived from immature embryos of both aneuploid and euploid plants were used in this study along with foundation seeds and a large number of their sexual progeny in order to discriminate between pre-existent variability and any novel variation induced by the in vitro culture. Only one translocation not described before and a new gliadin pattern were detected which could be ascribed to the effects of tissue culture, suggesting that this technique is not effective for inducing novel variation for breeding purposes in wheat.     

Plant Regeneration Through Anther Culture of Three Wild Species of Hordeum (H. murinum, H. marinum and H. bulbosum)

Plant regeneration was achieved through anther culture of three wild species of Hordeum (H. murinum, H. marinum and H, bulbosum). Calli or embryoids were formed from microspores in anthers cultured on a medium containing 6-benzylammopurine (BAP) and ficoll. These calli or embryoids regenerated green or albino shoots and roots after transfer to regeneration media. Green plantlets which developed on regeneration media were transferred to soil where they showed further growth.     

Oryzalin as an Efficient Agent for Chromosome Doubling of Haploid Apple Shoots in vitro

In an outbreeding species such as apple, haploid plants may be especially useful in breeding programmes for the production of homozygous material. However, methods must be available to induce chromosome doubling in the haploid plants. Two antimitotic agents, colchicine and oryzalin, were compared as regards their efficiency in inducing chromosome doubling of in vitro haploid apple shoots. Three colchicine levels (0.025, 0.25 and 1.25 mM) and three oryzalin levels (5, 15 and 30 μM) were evaluated. Three techniques were also used and compared. Survival rate and chromosome counts were determined. Differences were observed between the two antimitotic agents and between the three techniques. This study demonstrates that oryzalin could be a better choice than colchicine for chromosome doubling on haploid apple shoots in vitro.     

THE CALCULATING TEMPERATURE OF THERMAL CHARACTERISTICS OF NATURAL VENTILATION FOR A COLD FRUIT STORAGE DBTERMINATION

The paper analyzes the thermal characteristics of a natural ventilation cold stor-age,It shows that the calculating temperature in or outside the room is mainly effected by atmo-spheric temperature and the calculating temperature for a cold storage. They are determined by thelocal meteorological parameters.     

Genetic study of bolting and stem length in sugar beet (Beta vulgaris L.) using a factorial cross design

Summary The objective was to study the genetic basis of bolting and stem length in sugar beet full-sibs, developed by a factorial mating design (N.C. design II). The extent to which the inheritance of these characters can be attributed to the additive and non-dominance variation was investigated. The genetic analysis consisted of three sets (4×10, 4×8, and 3×8) of progenies. Estimates of additive genetic variance (² _A) and variance due to dominance deviations with some fractions of epistatic variance (² _D) were obtained for both characters. Bolting had a relatively large proportion of total genetic variance accounted for by ² _A. In most cases, non-additive effects were also important in determining the type of gene action in bolting. Stem length showed similar genetic variation to bolting susceptibility. Bolting resistance seemed to be dominant to the bolting susceptibility in most cases. Narrow sense heritability estimated for bolting was generally very large (0.93 to 0.96), which suggests that early generation selection for bolting resistance in a sugar beet population would be successful.     

Introgression of a gene for delayed pigment gland morphogenesis from Gossypium bickii into upland cotton

The presence of gossypol and its derivatives above the WHO/FAO standards (0.02–0.04%) in cotton seed oil and meal limits its usage as food and feed. To the contrary, the presence of pigment glands filled with gossypol and its derivatives helps to protect cotton plants from phytophageous pests. Thus a desirable cultivar would have glandless seeds on a glanded plant. This paper describes results on the successful introgression of this trait from Gossypium bickii into cultivated upland cotton. Five different tri‐specific hybrids (ABH1, ABH2, ABH3, ABH4 and ABH5) were obtained by crossing the amphidiploid F₁ (G. arboreum × G. bickii) with different gland genotypes of G. hirsutum as male parent. The hybrids were highly sterile, and their chromosome configuration at meiosis metaphase 1 (M1) in pollen mother cell (PMC) was 2n = 52 = 41.04 I + 4.54 II + 0.57 III + 0.04 IV. All five hybrids were similar in morphological characters, except for the gland expression and gossypol contents. The hybrid (ABH3) derived from genotype Gl₂Gl₂gl₃gl₃ of upland cotton (a single gene dominant line) had completely introgressed the target trait of G. bickii. While ABH1 and ABH2, which derived from recessive (gl₂gl₂gl₃gl₃) or dominant (GlGl) glandless upland cotton genotypes, had glandless seeds too, but the density and size of the glands on the plant were reduced significantly.     

AFLP analysis of genetic variability among Stylosanthes guianensis accessions resistant and susceptible to the stylo anthracnose

Stylosanthes guianensis, belonging to the genus Stylosanthes, is one of the most important tropical forage legumes and is native to South and Central America and Africa. Anthracnose, caused by the fungus Colletotrichum gloeosporioides (Penz.) Sacc., is a major constraint to the extensive use of Stylosanthes as tropical forage. Forty‐two accessions of S. guianensis were assessed with amplified fragment length polymorphism (AFLP) for genetic diversity and for resistance to anthracnose. In AFLP analysis, four selective primer combinations screened from 96 primer combinations were used to analyse these accessions, and a total of 225 clear bands were used for genetic similarity (GS) analysis, showing a 95.5% level of polymorphism on average. GS from 31.0% to 95.0% among the accessions was calculated with ntsys ‐pc software. The dendrogram was constructed with unweighted pair group method of averages (UPGMA) based on the AFLP data, and five clusters were defined at 48% GS. Two typical strains of C. gloeosporioides from Stylosanthes in China were used for anthracnose resistance screening. Most of the plant accessions showed variation in the reaction to two strains, and the correlation of resistance had a value of 0.904 (P < 0.01), suggesting common resistance to the two strains. The resistance accessions were randomly distributed in different groups of UPGMA clustering. These results demonstrate that AFLP analysis is an efficient method for evaluating the genetic diversity among S. guianensis accessions.     

Reduction in the yield and viability of carrot seed in relation to the occurrence of the plant bug Lygus campestris L.

Summary Research was carried out into the cause of a disorder occurring in seed plants of carrots characterized by backward fruits and resulting in a reduced seed yield.It appeared that both fertilization and initial development of the endosperm and embryo were normal, but that later on a sudden check in the growth of the fruit occurred, accompanied by disintegration of the contents of the ovule.Bugs of the species Lygus campestris L. were found to occur in considerable numbers on the seed plants of carrots. In experiments a reduced seed production with the same macroscopic and microscopic symptoms could be obtained when bugs were added to caged carrot umbels.It could be established that the presence of bugs caused not only a reduction in the seed production due to abortion of endosperm and embryo, but also a reduction in the germination percentage of the full-grown seeds due to embryolessness.When the bugs were brought on the umbels before or during anthesis the reduction in seed viability and expecially the reduction in seed production proved to be more serious than when the bugs were added after anthesis.