Awn Type Research Articles

An awn typology for Australian native grasses (Poaceae)

Australia has a large diversity of native grasses. The diaspores of many species possess awns that vary considerably in their number and shape. Some variations of awn shape have been found to be effective at diaspore dispersal. Although morphological descriptions of awns exist for most native grass species, the number of species that possess awns and the extent of awn variation is unknown. This makes it difficult to determine the evolutionary importance of awns and the potential function of the various morphologies. The aim of this study was to construct an awn typology based on morphological descriptions collated from published flora databases that will quantify the awn type diversity of all native grass species in Australia, and will inform awn type relationships and help to clarify the role of differing awn morphologies in diaspore dispersal. We found that 42.1% of 1000 Australian native grasses with a single awn type were determined to have a ‘significant’ awn. These could be classified into one of 20 awn types, the most common being (1) single, apical, geniculate (once-sharply bent) awns (93 species; 28 genera, especially Iseilema), (2) three, apically-attached, straight awns (59 species, mainly Aristida) and (3) single, apical, bigeniculate (twice-sharply bent) awns (46 species, mainly Austrostipa). Among Australian grasses, slightly (though significantly) more C3 species (49.2%) had awns than C4 species (39.9%), although the most common awn types in both contained sharply bent awns (bigeniculate and geniculate respectively). Our classification system will help to improve our understanding of the amount of awn morphological variation in Australian grasses and will enable further investigation into the important ecological role of awns in species fitness.

SpikeDroidDB: AN INFORMATION SYSTEM FOR ANNOTATION OF MORPHOMETRIC CHARACTERISTICS OF WHEAT SPIKE

The structure of the ear is one of the most important features of cereals associated with such agronomically important traits as productivity, resistance to environmental factors and pests, threshebility. Ears differ in shape, size, density, awnedness, color, etc. Analysis of the ear traits requires visual inspection, manual measurements and is very time-consuming. The effectiveness of ears’ phenotyping can be improved by the introduction of an automated image processing technology, storage of information in databases, use of machine learning algorithms to analyze this information. This paper presents a new approach for collecting, storing and analyzing of information about morphometric characteristics of ears of wheat. Two protocols for obtaining digital images of the ear have been developed. The computer-aided information system SpikeDroidDB has been developed, which allows you to store digital images of the ear, annotate their phenotypic features (14 features, including plant variety description, links to parent genotypes, generation, planting number, ear morphology description). The interface provides a flexible query system to access the data. SpikeDroidDB represents an interconnected representation between genotype, phenotype, location, and growing conditions. The web interface of SpikeDroidDB is available at http://spikedroid.biores . cytogen.ru/ and allows you to work with the system as with desktop computers or mobile devices. We used SpikeDroidDB for the digitization and annotation of a collection of ears of F 2 hybrids from crosses between the Australian cultivar of common wheat Triple Dirk and accession KU506 of Chinese wheat Triticum yunnanense. This experiment includes analysis of 104 plants, 230 spike images. The analysis of the variability of ears in form, length, and other traits allowed determination of the type of their genetic control: compactness is controlled by two recessive genes, awn type and hairi ness at the site of attachment of the spikelet to the axis is controlled by single dominant gene type, hairiness on the axis of the spike is controlled by two dominant genes.

한국에서 개발된 총체사료용 보리 품종의 형태적 특성

국내 보리 소비가 급격히 감소하면서 재배 면적도 줄어들어 겨울철 논을 이용한 보리 재배 농가의 대체 소득원이 보리를 활용한 조사료 생산이다. 경지이용률 제고와 양질의 조사료 공급은 국내 축산 농가의 국제경쟁력을 올릴 수 있어 최근 청보리의 생산은 현저히 증가하고 있는 추세이다. 총체사료용 청보리는 식용보리에 비하여 전체적인 건물수량성이 높아야 하고 가축이 먹기에 좋도록 형태적으로도 개선되어야 한다. 그 동안 개발된 총체사료용 청보리는 벼와의 작부체계에 알맞도록 조숙이면서 건물수량이 ha당 10<TEX>$\sim$</TEX>12톤 (생체수량 평균 33톤/ha)을 보이는 영양, 선우, 상원, 소만 등을 개발하였으며, 가축의 기호성이 좋도록 거친 까락을 매끈망으로 개선한 우호, 까락이 퇴화한 삼차망 보리 유연과 줄기에 잎귀를 없애서 부드럽게 만든 다미 등 초형을 개선하였다. 이러한 사료 전용 청보리 품종들은 사료가치도 우수한 것으로 평가되어 육종적으로 개선한 각 품종들의 고유 생육특성을 중심으로 보고하는 바이다. In Korea, domestic consumption of barley as a cereal crop has been decreasing since the 1980s. It has been considered that winter-season crop production could enhance the global competitiveness of domestic livestock industry by providing better quality fodder to livestock and enhancing field use rate. Therefore, the purpose of barley cultivation for cereal food production has been recently replaced by the production of forage barley. Consequently, the area of barley cultivation for forage is markedly increasing in Korea. Forage barley is cultivars especially as forage for cattle. While any type of barley can be used as forage for feeding cattle, forage barleys deliver a higher dry matter yield than conventional feed barley. We have developed forage barley cultivars with cattle's favorite characters such as smooth awn, hood and auricleless types. Cultivar Wooho, Yuyeon, and Dami have smooth awn, hood type spike, and auricleless type plant. We also developed rough awn type barley cultivars, such as Yongyang, Sunwoo, Sangweon, and Soman, showing earlymaturing and high-yielding. They showed about 12 to 10 ton ha－1 in dry matter yield (average 33 ton <TEX>$ha^{-1}$</TEX> in fresh matter yield). And these were evaluated by forage quality which showed a higher grade of silage quality (TDN, ADF, NDF, CP, etc.) for whole crop barley use. Based on these results, it indicated that barley with smooth awn, hooded, and auricleless could be suitable sources in breeding for whole crop forage use.

Patterns of phenotypic diversity in an Ethiopian barley collection, and the Arussi-Bale Highland as a center of origin of barley

485 land race populations of barley collected from 91 Minimum Package areas spread over 12 provinces of Ethiopia were grown in the field and classified for number of kernel rows, spike length, awn type, spike density, rachilla hair, caryopsis, and kernel color. The different characters showed different levels of diversity by the Shannon-Weaver diversity index. Provinces were grouped into regions to detect possible differences in diversity within and among regions. Much of the variation in diversity is due to differences among characters; and no differences were detected among provinces and regions in the level of diversity, which could be due to insufficient sampling. A high diversity index (H'=0.72) was obtained for the Southwestern Plateau, and this was not significantly different from the value for Ethiopia (H'=0.68). Clinal patterns of variations were observed for some characters and localized concentrations for others. An attempt was made to explain these patterns based on climatic data and selection. Vavilov's theory of the emancipation of recessives was found to be untenable. A center of origin of barley is defined on the Arussi-Bale Highland in accordance with the requirements of the current concept of the center of origin; and the inadequacy of this concept is discussed. Disruptive selection is considered as the most probable cause of the maintenance of the diverse forms of barley in Ethiopia; and further detailed studies of the patterns of variation of barley in Ethiopia are recommended.

Genetic diversity in japonica rice landraces (Oryza sativa) from the Taihu Lake region

The Taihu Lake region has a long history of cultivating rice (Oryza sativa L. sub. japonica) and has a high yield of rice. However, the genetic basis of rice varieties is becoming more and more narrow, which may result in potential risk to agricultural production. In order to enlarge the genetic basis of rice varieties by virtue of local varieties, we examined the genetic diversity of 823 varieties of japonica rice landraces from Taihu Lake region. We found that, among the 19 traits studied, the coefficient of variation of 15 quantitative traits ranged from 4.6% (seed setting rate) to 33.7% (yield per plant). There existed 10 phenotypes for husk color, 6 for apiculus color, 5 for awn type, and 4 for grain shape, respectively. For the 19 traits, the phenotypic diversity index (H') ranged from 0.757 (grain shape) to 1.930 (filled grains per panicle), av-eraging 1.540. Phenotypic variance of accessions headed after 10 September was larger than that of acces-sions headed before 10 September (including this day). Principal component analysis showed that plant height, panicles per plant, spikelets per panicle, filled grains per panicle, spikelet density, 1,000-grain weight, yield per plant, and panicle neck length were important traits in explaining the phenotypic diversity of japon-ica rice landraces from the Taihu Lake region.

Genetic studies on net blotch resistance in a barley cross

An investigation was initiated to study the genetics of resistance to three isolates of Pyrenophora teres (WRS102, WRS858, and WRS857), which have been routinely used for screening for net blotch resistance in Canada. The F1, F2, and doubled-haploid lines were derived from a Leger/CI9831 cross of barley (Hordeum vulgare L.). These materials, along with their parents, were inoculated with each of the three isolates at the three-leaf stage in growth chambers. Results showed that resistance to WRS102 was controlled by three recessive genes, resistance to WRS858 by one recessive gene, and resistance to WRS857 by either one dominant gene or two complementary genes. One of the WRS102-resistance genes appeared to be on chromosome 2 and another linked to the WRS858-resistance gene. Resistance to these three isolates was not associated with awn type, esterase 1, and esterase 5. Selection for resistance to WRS102 and WRS858 would be more effective than selection for resistance to WRS857 in a conventional breeding program. Key words: Barley, Hordeum vulgare, net blotch, Pyrenophora teres, haploids

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

AbstractThree 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.

Variation in the Morphology of the Spike within Ethiopian Barley,Hordeum vulgareL. (Poaceae)

Abstract Barley (Hordeum vulgare L.) samples were collected from different regions in Ethiopia and grown in a lath house. Spikes were identified and 290 of them representing 64 morphotypes (“varieties”) selected on the basis of morphology and provenance. These were categorized for spike row number, caryopsis type, rachilla hair type, spike length, awn type, spike density and kernel colour; and classified (TWINSPAN) giving 42 groups. Six-row covered and naked, two-row nutans covered and naked, and deficiens covered types were found. Some morphotypes are found in higher proportions than others in some regions and localities. From one to twelve morphotypes occur per field; the overall average being three morphotypes per field.

A Diversity Analysis of a World Collection of Barley1

Data on more than 17,000 accessions of the barley (Hordeum vulgare L.) world collection maintained by the USDA, SEA, were analyzed for variation of five morphological characters (growth habit, caryopsis type, awn type, kernel row number, and kernel color). Phenotypic frequencies within the accessions from each of 48 countries, grouped in 14 regions, were tabulated. Polymorphism was widespread in most countries for different sets of characters. Very weak east‐west clinal patterns were observed and this analysis only partially supported the earlier reported patterns of variation in the postulated centers of diversity. This result may be due to an inadequate sample of characters available for analysis and/or an inadequate number of geographic regions in the world collection.The H' diversity index was computed for each country and region, for individual characters, and after pooling all five characters. Analyses indicated the between‐regions component of diversity to be relatively smaller than the variation in H' among characters and among countries within regions. This analysis shows no distinct geographical patterns in these data, but its use with additional data is warranted.

NATURAL SELECTION IN A COMPOSITE CROSS OF BARLEY

A composite of 105 crosses involving 15 parental barley varieties was grown for 5 years at nine stations of widely different latitudes in Canada, U.S.A. and Norway. A resulting sample of seed was recovered from each station and grown with original seed in comparative studies at Edmonton. Significant differences were observed among plants from different stations for heading date, maturity period, yield, spike type, and awn type. Little difference was observed for plant height and seed size. There was little or no effect on collar type, neck shape, neck length, leaf width or shape of basal rachis internode. Natural selection acted strongly against black kernel, the elimination of which was probably due to genetic linkage with a character of low competitive capacity. In general, the shift in the gene pool was consistent with plant breeding objectives.

Studies on artificial selection of gametophyte (pollen) in relation to plant breeding in two-rowed barley. I. Selection of some qualitative characters by high temperature treatment of F&lt;SUB&gt;1&lt;/SUB&gt; spikelets just before flowering.

When some Mendelian populations are grown successively under different conditions for several generations, they come to have diffcrent gene constitutions. The mechanism of this alteration has been mainly explained by occurrence of individual selection in the populations. It is said, however, that gametophyte selection may play an important role in this alteration. This study was conducted to clarify the existence of gametophyte selection by high temperature treatment of F1 Spikelets of tworowed barley just before flovyering. Materials and characters used in this study are shown in Table 1, and these characters were ascertained to be controlled by one gene having no linkage relation among them. Several ears of one F1 plant were put into warm water, 36-39°C, for 4 minutes just before flowering and the remaining ears of the plant were fertilized under natural conditions as the control. Segregation ratios of some qualitative c'haracters in F2 generation of the former were compared with those of the latter. About 30 F1 plants in each cross combination were treated. Segregation ratios of the four characters -awn type, lateral floret type, awn or awnless in lateral floret, and hair or hairless in leaf sheath- in monohybrid and dihybrid F2 generations, agreed with the expected values in both cases of treament and control (cf. Tables 2, 3-a, -b, -c, 4, 5 and 6) .

INHERITANCE OF SAWFLY REACTION AND STEM SOLIDNESS IN SPRING WHEAT CROSSES: STEM SOLIDNESS

Inheritance of stem solidness was studied in populations of F3 and B2 lines from the Red Bobs × C.T. 715 and Redman × S-615 (Triticum aestivum L.) crosses and backcrosses. The data supported the hypothesis that the varieties in each cross differed by four genes for stem solidness. In both crosses, one gene exerted a major influence in that its allele for hollowness in the homozygous condition was epistatic to the other three genes. The other three genes within each cross were similar in their influence on solidness. Between the two crosses, corresponding genes differed in some degree.Genetic analyses and correlation coefficients both revealed a close association between sawfly resistance and stem solidness in the Red Bobs × C.T. 715 cross indicating that the stem solidness character was largely responsible for conditioning the degree of sawfly reaction in a plant.In both crosses, a weak negative correlation was found between stem solidness and height. Stem solidness was not associated with bunt (race T-2) reaction, glume color, awn type, or heading date.

INHERITANCE OF BUNT REACTION IN A REDMAN × S-615 WHEAT CROSS

Inheritance of reaction to race T-2 of Tilletia caries (DC.) Tul. was studied in populations of F3 and B2 lines from the cross Redman × S-615 (Triticum aestivum L.) and the respective backcrosses. Redman and S-615 were found to differ by three genes for bunt reaction. Redman possesses a major gene recessive for resistance, and two minor genes. Each of the minor genes is capable of conditioning a moderate degree of resistance alone but together they are capable of conditioning high resistance as a result of geometric gene actionCorrelation coefficients show that bunt reaction to race T-2 is not associated with wheat stem sawfly (Cephus cinctus Nort.) reaction, total stem solidness, solidness in each internode, awn type, glume color, plant height, or heading date.

INHERITANCE OF RESISTANCE TO ERYSIPHE GRAMINIS F. SP. HORDEI IN BARLEY: I. THE INHERITANCE OF RESISTANCE IN TWO VARIETIES IMMUNE TO RACE 8

The inheritance of resistance to a culture of race 8 of powdery mildew was studied in the resistant barley varieties Ottawa 5069-40 and B294. Ottawa 5069-40 possesses one dominant gene for resistance which is probably the gene from the variety Duplex. B294 possesses two dominant genes for resistance. The three resistance genes are inherited independently. No linkage was detected between the resistance genes and the genes for row number, awn type, and rachilla hair length.

INHERITANCE OF BUNT AND LOOSE SMUT REACTION AND OF CERTAIN OTHER CHARACTERS IN KOTA × RED BOBS AND GARNET CROSSES

Genetic studies were made in F2, F3 and F4 on the progeny of two common wheat crosses, Kota × Red Bobs and Kota × Garnet. Two chlamydospore collections from pure line hosts were used for inoculation in the bunt studies. The heritable nature of bunt reaction was clearly demonstrated in these crosses and evidence obtained that the degree of resistance found in Garnet must be conditioned by a single major factor. No genie hypothesis could be offered to explain the findings in regard to loose smut reaction due to a lack of agreement in infection percentages in the F3 and F4. Red kernel color in Kota and Red Bobs was found to be governed by two factor pairs. The results on the inheritance of awn characters agreed with the earlier findings of Clark and other workers with crosses of similar awned types, several factor pairs being involved. Two main factors appeared to condition the difference in strength of straw between Kota and Garnet, but the entire expression of the character can best be explained on a multiple factor basis. Correlated inheritance studies, made with the use of the correlation ratio η, indicated the presence of two linkage groups concerned with reaction to the bunt forms used. However, the linkage apparent between strength of straw and bunt susceptibility factors and between awn type and bunt resistance factors is not considered to be close enough to interfere with breeding for desirable bunt resistant varieties.