Short Awns Research Articles

Idiopappus quitensis gen. et sp. nov. from Ecuador (Asteraceae: Heliantheae)

The opposite-leaved Idiopappus quitensis of Ecuador is a new genus and species related to the alternate-leaved Monactis H.B.K. and Kingianthus H. Robinson that have 0 or 1 pappus scales. Characteristically, the ray achenes of Idiopappus bear 3 short awns and the disk achenes bear 2 squamae.

A Note on Jansenella (Gramineae)

In my account of the Arundinelleae, Kew Bull. 37(3): 489 (1982), I noted that several features of the anatomy suggested that Jansenella may be a C3 grass. This would be surprising in view of the fact that all the other members of the Arundinelleae are C4 grasses. Unfortunately, at the time of the original investigation it was not possible to obtain a good C3 starch stain that could give convincing support to the conclusions drawn from the anatomy. However, through the kind assistance of Richard Burleigh of the British Museum Research Laboratory, I was able to obtain an isotope analysis for Jansenella. The result of this analysis showed quite positively that Jansenella is a C3 grass (delta 13c 0/00, rel. PDB = 27-7). On this evidence, and also because of the membranous ligule and punctiform hilum, Jansenella is considered to be a primitive member of the tribe Arundinelleae. Since the account was written of the leaf-blade anatomy of the Arundinelleae a newly described genus has had to be considered for inclusion in the tribe. Chandrasekharania Nair in Proc. Ind. Acad. Sci. 91: 79 (1982), an Indian genus, has 2-flowered, papery brown spikelets with both florets hermaphrodite and the lemmas bidentate with a short awn from the sinus. When a cross-section of the leaf-blade was stained for starch the chlorenchyma showed a strong positive reaction, indicating that Chandrasekharania is a C3 grass. Its leaf-blade anatomy is identical with that of Jansenella and for this reason and the nature of the spikelet morphology it is considered to be the most primitive member of the Arundinelleae. This genus and Jansenella together suggest a possible link between the sub-families Panicoideae, in which the tribe Arundinelleae is included, and Arundinoideae.

Effect of Awn Length and Naked Caryopsis on Malting Quality of Betzes Barley1

Plant breeders at the Montana Agruicultural Experiment Station developed four isogenic ‘Betzes’ lines from a Betzes*7/‘Sermo’ barley (Hordeum vulgare L.) cross. The four isogenes were long‐awned covered (Lk2Lk2NN), long‐awned naked (Lk2Lk2nn) short‐awned covered (lk2lk2NN), and short‐awned naked (lk2lk2nn). These lines and Betzes were grown in a total of 11 environments in the western United States in 1970 and 1973.Of the four experimental isogenic lines, the two covered types produced the most grain and were similar to Betzes in this trait. The long‐awned naked line produced 91%, and the short‐awned naked 89%, of Betzes. Grain from each location was malted separately. Long awns produced significantly heavier kernels, higher percentage of plump kernels, lower diastatic power, and lower alpha amylase activity than short awns. Naked caryopsis conditioned significantly higher barley protein content, higher malt extract, a higher finecoarse grind extract difference, lower kernel weight, lower percentage of plump kernels, lower kernel color score, lower wort color, lower wort N:malt N, lower diastatic power, and lower alpha amylase activity than the covered caryopsis. Genotypes with the covered allele averaged about 10% greater grain yield than did the naked genotypes.

Genetic Diversity of Weedy Rye Populations in California1

Eight populations of weedy rye, Secale spp., from the Cascade range counties in northern California were scored for characters describing the wild and cultivated gene complexes. The relative frequencies of individuals with non fragile rachis, short awn, blue aleurone, and bronze lemma represent the postulated gene flow by introgression from cultivars into the original Secale montanum Guss. × S. cereale L. hybrids giving rise to the present genetic diversity and geographical patterns of variation in weedy rye. Although characters representing the wild and cultivated forms are not associated into distinct gene complexes, the weedy rye populations have a varied mixture of them. This confirms an earlier report on the origin of weedy rye and suggests continuing genetic shifts in weedy rye toward the cultivated forms.

Characteristics and inheritance of radiation-induced mutations in barley II. Two short-awned mutations

Two mutations were obtained in a two-rowed, spring-type barley variety, Asahi No. 5. KM 114 was obtained in the X2 population of X-irradiated dormant seeds (15 Kr) and KM 218 was found in X2 of gamma-irradiated seeds (15 Kr). KM 114 had very short awns, short plant height, almost normal spike size, and narrow and thinner seeds with pointed tip. The mutant gene is Mendelian recessive. KM 218 plants were normal or slightly taller, had somewhat larger spike, with somewhat longer rachis internodes, medium-long awn, and slightly longer, narrower and thinner kernel than those of the parental variety. At maturity, grains are exposed in many seeds (semi-naked kernels). This mutant also has a conspicuous diagnostic trait; the abnormal development of rachilla into extra florets, some of which set seeds. This mutant gene is also Mendelian recessive. Genes for these two mutants are not allelic and are inherited independently as indicated in F2 and F3 analyses. Genes of these two mutations will serve as good marker genes in genetic and linkage studies in barley, because their character expression is consistent and the recessive homozygotes are viable and fertile.

Isogenic Analysis of Strontium‐89 Accumulation in Barley1

The effect of short segments of chromosomes on Sr‐89 accumulation in barley, Hordeum vulgate L., was studied by comparing Sr‐89 accumulation in pairs of isogenic lines. The members of each isogenic pair differed by segments of chromosome estimated to be less than 6 recombination units in length.Six of the 11 chremosome segments studied influenced Sr‐89 accumulation in grain, stems, or leaves of mature plants or in shoots of seedling plants. In three of the segments the marker gene that served to identify the segment appeared to effect the differential accumulation of Sr‐89. The three genes were those that control hoods vs. awns, long vs. short awn, and naked vs. covered caryopsis. In addition, the chromosome segments identified by the genes controlling two vs. six rows of kernels, black vs. white lemma and pericarp, and purple vs. nonpurple lemma and pericarp had a significant effect on Sr‐89 accumulation.The study leads to the conclusion that the genetic basis for differences in Sr‐89 accumulation involves a number of genes and is highly dependent on the genetic stocks involved.

Genetical studies on ear-type affecting kernel shape in naked barley : I. Comparison of young ear developments among naked barley varieties

Ears and awns of barley vary in length. TAKEZAKI(10) made an extensive study on the characteristics of awns and ears in relation to their lengths. Short awns were associated with short or medium ars ; medium-long and long awns with long ears. He classified cultivated barley into eight different types, Ds, Dm1, Ms, Mm2, Mm1, Ml, . Lm2 and Ll, based on average awn length (i. e. s-5cm, m-8cm, m-10cm and l-15cm) and on average ear length (i. e. D-5cm, M-8cm, and L-11cm). Main varieties cultivated in Tokai-Kinki district were restricted to Mm1 and Dm1 types. However, these varieties were different in width of the lateral kernel rows. The ear width varide in the upper, central and lower parts of a spike. In this study, morphological observations of the ear development were made at different stage I to X were made by microscopic tests following INAMURA's method(5) and the ears from the ear stage X to the heading stage by the use of magniging glass. The results of these observations which have been presented in tables and figures of the text are summerized as follows: 1)Using three varieties bilonging to the same ear type (Mm1) and one belonging to a different ear type (Dm1), measurements of the ear width of young ears were made at defferent locations on a spike (upper middle and lower parts) both in main and lateral kernel rows. Also the number of spikelets per ear and the internode length of spikelets were measured. Authors studied these characteristics of young ears in relation to the widths of young ears and other characters. 2)The developmental difference between Mm1 and Dm1 appeared during the period between March 20 and ripeness. The varietal difference sithin Mm1 also appeared during the same period.

A Morphologically Distinct Ecotype of Dactylis glomerata L.

PLANTS of Dactylis, both diploid and tetraploid, from the Mediterranean region can be included on purely morphological grounds within the limits of Dactylis glomerata ssp. hispanica (Roth) Nym. There is only one constant feature of this taxon, described by Domin1 as follows: “the typical ssp. hispanica in one form or another has lemmas divided into two blunt lobes from the middle of which grows a very short awn, or a mere point, which sometimes does not even reach the size of an awn; sometimes the lobes are pointed”. Many Mediterranean populations of this broad type have now been studied at Aberystwyth, and among them a form of particular morphological interest has been found.

A preliminary note on the X-ray mutants of Pusa (52) wheat

As a result of X-ray treatment of young seedlings of Pusa (52) wheats, eleven mutant types were separated. Of the eleven, 4 are awned types and the rest awnless—the degree of awnlessness varying from short awns to no awns. The spikes of the mutants, in the first year, are much smaller than the spikes of Pusa (52). This is probably due to the disturbances caused by X-ray treatment of the seedlings. The spikes of all the 11 types of mutant, show a much greater length in the next generation.