Panicle Branches Research Articles

蛍光色素染色による穂いもち感染部位の観察

Rice panicles spontaneously infected with Pyricularia oryzae Cav. were stained with calcofluor white to impart fluorescence to fungal structures. The procedure facilitated observation of conidiophores and conidia formed on infected sites such as neck, rachis, panicle branch, pedicel and husk, and of invading hyphae in the cells of neck, rachis and panicle branch. It is also possible to observe conidia attached to the epidermis of neck, rachis, panicle branch, pedicel and husk.

Azide mutagenesis in rice

Seeds of rice cultivars viz Jaya, IET 5656 and Fujiminori presoaked for 24 h were treated with 0·001, 0·002, 0·004 and 0·005 molar concentrations of sodium azide at pH 3 for 4 h with a view to investigate its mutagenic action in rice. The percentage of germination, survival, seedling height and leaf number decreased in the treated population with a few exceptions. Cytologically abnormal plants were not detected in any of the treated population. Plant height, panicle branches, seed set and panicle grain weight decreased in the azide treated population whereas tiller number increased in Jaya and Fujiminori cultivars. The frequency of chlorophyll mutants induced was more in Jaya less in IET 5656 and the least in Fujiminori 0·005 molar concentration was found to be the most effective for inducing chlorophyll mutations in IET 5656 and Fujiminori. The same concentration induced more morphological mutants in all the 3 cultivars. Morphological and physiological mutants isolated include the tall, semidwarf, dwarf, early and late flowering mutants, protein rich mutants, grain shape mutants and many others. Varietal differences are indicated in the induction of seedling injury and of chlorophyll and morphological mutants produced.

Production of Haploid Saccharum spontaneum L. - Comparison of Media for Cold Incubation of Panicle Branches and for Float Culture of Anthers

Means were sought to increase the frequency of haploid production from anther cultures of Saccharum spontaneum L. Excised preemerged panicle branches were incubated in modified Murashige-Skoog (MS), Nitsch (H), Gamborg (B5), and Chu (N6) media at 10 °C for 4 to 10 weeks prior to removal of the anthers for culturing at 27 °C. Anthers, either continuously cultured on liquid media or floated on liquid media 1 to 8 weeks prior to nurse culture, produced visible calli in 30 days. Nearly 1% of the anthers in one clone, SES 208, produced calli. The calli increased in mass on nurse medium containing 0.25 to 0.50 mg · l(-1) picloram as the auxin source and differentiated into green calli when the picloram was reduced to 0.05 to 0.125 mg · l(-1). The green calli developed into plants on lowered-picloram or picloram-free media. Calli and green plants were obtained from all three clones studied. Plants were regenerated from 100 out of 276 callus lines. Seventeen plant lines have been transferred to greenhouse culture. Four of seven plant lines checked for ploidy were haploid, two were diploid. A method utilizing stomate guard cell lengths was developed as a means to estimate ploidy level. The increased success in haploid callus and plant production is thought to be the result of long cold treatment of panicle branches, use of low salt media for panicle treatment in the cold, use of picloram in place of 2,4-D in the nurse culture, and use of a high nitrate/ammonium ratio in the liquid culture.

Morphological variation and taxonomy of thePoa macrocalyx complex (Poaceae) in Hokkaido

Morphological features of 41 local populations of thePoa macrocalyx complex from the seasides of Hokkaido were analyzed with special reference to the following seven characters: spikelet length, number of florets per spikelet, relative length of side nerves to the entire length of the first glume, that of the second glume, length ratio of the second glume to a spikelet, ratio of length of the closed part vs. entire length of leaf sheaths, and scabrousness of panicle branches and pedicels. All of these characters varied continuously, and considerable degrees of variability within a population were observed. However, separation of populations into three groups became evident when the data were subjected to principal component analysis and also to a method of examination which was devised for identification of a population (not an individual) of this complex. The three groups that resulted from morphological studies were exactly in parallel with the grouping of populations supported by differences of chromosome numbers and geographical distribution. Evolutionary differentiation of this complex was discussed in connection with polyploidy and gametophytic apomixis. As a result of taxonomic considerations, the plants were arranged in three emended varieties of one species:Poa macrocalyx var.fallax, P. m. var.tatewakiana, P.m. var.scabriflora.

Haploid Production From Anther Culture of Saccharum spontaneum L.

Summary Initiation of microspore multicellular development in anther cultures of Saccharum spontaneum L. was stimulated by preculture treatment of panicle branches at 10°C for 21 d. This prolonged cold treatment killed young microspores and switched the development of nearly mature microspores from a gametic to a sporophytic route. Anther cultures produced microspore-derived calli in four of the ten clones tested. Calli of two clones yielded plants; one line was haploid, the other diploid.

Role of the Hull in the Ripening of Rice Plant : VII. Effects of supplying of silica and potassium during reproductive growth stage on the form and function of hulls

Previously, and were shown to accumulated in the hulls of fertile grains than those of sterile ones. Based on these findings, effects of supplying of and during reproductive growth stage on the form and function of hulls were further studied. And the effects of top dressing of new fertilizer potassium silica were also investigated. 1. Silica. (a) No significant difference in the number of spikelets on the primary branches of panicle was detected between no-supplying and supplying plot, whereas the number of spikelets on the secondary branches was increased by the supplying of silica. (b) Ripening percentage and weight of 1000 kernels increased significantly by supplying of silica. This might be due to the increase in the size of hulls and the decrease in the occurrence of malformed grains. (c) The content in hulls increased greatly by the supplying of silica. 2. Potassium. Supplying of during reproductive growth stage gave mostly the same effect as those of silica, however the difference in content was very small between no-supplying and supplying plot. 3. New fertilizer potassium silica The top dressing of silica, a new fertilizer, at initial stage of spikelets differentiation enhanced the ripening percentages and weight of 1000 kernels due to the decrease in the occurrence of malformed grains. As shown above, and affect the form and function of hulls and were very useful and important to increase ripening.

The Stylet Sheath as an Indicator of Feeding Activity of the Rice Stink Bug2

Tan, volcano-shaped, stylet sheaths of Oebalus pugnax (F.) were found on developing grains and branches of the rice panicle. The sheaths were weakly attached to the surface of the plant tissues. Stylet sheaths were used to study the feeding activities of the rice stink bug. All immature stages, except Stage 1, fed on and damaged grains similar to adults. Adult rice stink bugs produced more stylet sheaths at 25° than at 30° and 35°C. Male rice stink bugs produced ca. half as many stylet sheaths as females.

Spikelet Abscission in Guineagrass as Influenced by Auxin and Gibberellin1

Seed production of guineagrass (Panicum maximum Jacq.), an important pasture and forage crop in the tropics, is hindered by its heavy loss of seeds through spikelet abscission. A method whereby abscission could be delayed or arrested would be a great aid in seed harvest of this and other Panicum species.Auxin and gibberellin at three concentrations (10‐3, 5✕10‐3 and 10‐2M) were applied to the inflorescences of two experimental genotypes (PM285 and 68s‐5‐2) when the panicle was three‐fourths emerged from the flag leaf to inhibit spikelet abscission. Growth chamber and field experiments were conducted.Response was dependent on plant genotype and growth regulator concentration. In the growth chamber, panicle branch explants were inserted into semisolid agar solutions of growth regulators. The most responsive auxin treatment inhibited abscission by 32%. In the field, aqueous sprays of growth regulators were app.lied to entire inflorescences. The most responsive auxin treatment inhibited abscission by 40%, The two genotypes responded differently to IAA treatment with 68s‐5‐2 exhibiting significantly less abscission than PM285. Gibberellin treatments either stimulated abscission or had no influence under the conditions tested.Histological sections of pedicels of the genotype 68s‐5‐2 were made to follow the development of the abscission zone with and without applied auxin. The abscission zone exhibited no readily observable morphologlc or histologic response to auxin.

Genetical Studies on Dense and Lax Panicles in Rice : I. Character Expression and Mode of Lax Panicle Rice

In order to get information on the genetical mechanism of panicle formation in rice, the character expression of lax panicle rice and its mode of inheritance were inves-tigated. It was observed that the panicle density of rice was dependent not only on the number of spikelets and panicle length, but also on the total number and total length of primary and secondary branches, although their effects on the panicle density varied largely according to the cultivars and strains used in this study. Thus, we recommend the ratio of total spikelets to total length of rachis and primary branches of panicle as the most efiicient method to determine the panicle density in rice at least in so far as the cultivars and strains used in this study are concerned. The spikelet formation of a strain, Soryuto, which has a high laxness, was remarkably responsive to low temperature. When this strain was treated with low temperature at the panicle differentiation stage, various kinds of malformed spikelets were frequently induced. In the extreme cases, no spikelet developed on the panicle branches. In the cross between Soryuto and the dwarf mutant strain induced from a cultivar, Akibare, by X-irradiation, it was found that Soryuto carried a singie recessive gene responsible for the lax: panicle, which was independent of the dwarf gene. The pronounced gene interaction was also observed between the lax panicle gene and the dwarf gene.

Genetical Studies on Dense and Lax Panicles in Rice : II Character Expression and Mode of Inheritance of Dense Panicle Rice

Following the previous paper (1979) dealt with the lax panicle rice, this investiga-tion was conducted to get information on the character expression of dense panicle rice and its mode of inheritance. It was found that the dense panicle cultivars and strains, in general, possessed either greater number of spikelets and panicle branches, or shorter panicle and primary branches than the normal type cultivar, the, causes for dense panicle being largely varied with the cultivars and strains tested. In some cultivars and strains which had extrerne dense panicles, the occurrence of tertiary branches was observed. It was verified that the newly devised method, that is, the ratio of total spikelets to total length of rachis and primary branches, by which the panicle density of normal and lax panicle rices would be satisfactorily esti.mated, as described in the previous paper (1979), could also be applied to the dense panicle rices. Crosses between a dense panicle mutant strain and its original cultivar. Akibare, and between the former and a dwarf mutant strain induced in Akibare were mad, e, and the segregations of panicle density and its related characters were investigated in F2. It was shown that the dense panicle mutant strain carried a single recessive gene respon-sible for the dense panicle, which was tentatively designated as dn. Positive gene interaction was also observed between the dense panicle gene and the dwarf gene

Dormancy of Kentucky Bluegrass Seed in Relation to the Color of Spikelets and Panicle Branches at Harvest1

One of the most important factors affecting germination of Kentucky bluegrass (Poa pratensis L.) seed is maturity at harvest. This study evaluated degrees of seed dormancy in 10 cultivars and selections of Kentucky bluegrass harvested at various stages of change in color of spikelet and panicle branches from green to brown.Significant differences in the degree of dormancy at different stages of change in color of panicle branches existed among the entries. ‘Merion’ exhibited the most prolonged dormancy of seed during this period of change in color. The reduction in dormancy was generally accompanied by changes in color, of the panicle branches in particular, from green to brown. A color index was, therefore, proposed to determine the right time for harvesting Kentucky bluegrass seed to obtain maximum germination.

Basis of Heterosis in the Differentiating Sorghum Panicle1

Heterosis in grain sorghum (Sorghum bicolor L. (Moench)) yield has been previously traced to heterosis in the number of grains per basal branch in the panicle. A comparative quantitative morphogenetical study of the differentiating panicle was performed to explore the origin of this heterotic effect. Field grown plants of RS 610 hybrid and its two parental lines (B‐Combine Kafir 60 and Tx 7078) were dissected and studied microscopically.Heterosis (advantage of the hybrid over both parental lines) was identified in faster formation of primary and secondary panicle branches; faster panicle growth rate and larger primary basal branch primordia. The hybrid did not differ from the parental lines in the number of branch whorls per panicle, growth rate of basal primary branches, and the length of time period between spikelet and floret initiation.Heterosis in the number of grains per basal primary branch was traced to two major factors: (1) a larger reproductive apex that allowed development of larger basal branch primordia, and (2) a 4‐day time‐lapse between termination of the acropetal formation of branches and the onset of the basipetal formation of spikelets. This time‐lapse was utilized in the hybrid for the increase in basal branch size prior to spikelet initiation.

High Temperature Injury of Ripening in Rice Plant : V. On the barly decline of assimilate storing ability of grains at high temperature

A jabonica rice (cv. Norin-17) was used to test the effects of high temperature treatment (day-night, 35-30°C) combined with the treatments which increase or decredse the available carbohydrate amount per grain, upon the ripening of rice grains. 1) Under high temperature, the rate of ripening was much higher at an early ripening period, but the inflow of assimilates into grain ended earlier (2 to 3 weeks after flowering), resulting in lower 1000-kernel weight than that of normal outdoor temperature. 2) At both high and normal temperatures, 1000-kernel weight was incredsed by thinning the panicle branches and was decreased by leaf-cutting or fertilizer dificiency. At high temperature, panicle thinning increasd 1000-kernel weight about 10%, while at normal temperature about 20%. 3) At both temperatures, the amount of TAC (total sugar plus crude starch) accumulated in each shoot was greatest at the no-treatment control, being fllowed in order by fertilizer deficiency, panicle-thinning and leaf-cutting. The total nitrogen accumulatlon was also greatest at the control, being followed by panicle-thinning, leaf-cutting and fertilizer deficiency. Panicl/Straw ratios in dry weight and in TAC amount at high temperature were lower than at normal temperature, indicating a relativelvy less TAC translocation into the panicle, leaving relatively more amount in the straw at high temperature. 4) An addition of CO2 to the ambient air combined with the above treatments did not increase the 1OOO-kernel weight at both temperatures indicating that CO2 amount was not limiting in this experiment. 5) The 1000-kernel weight did not increase at all after moving the plant from high to favorable temperatures if the plants had been treated at high temperature about 2 weeks after anthesis, whether the as-similate amount which should be stored in each grain was increased or decreased. (3) It was assumed that the main cause of early stoppage of maturation with a small 1OOO-kernel weight at hightemperature was an early decline of storing ability of assimilates in panicle rather than the decficiency of assimilate amount in the plant

‘Cougar’ Kentucky Bluegrass Seed Production as Affected by Clipping to Stimulate Grazing1

This study was conducted to determine the seed production responses of ‘Cougar’ Kentucky bluegrass (Poa pratensis L.) to clipping at different times from early fall through late panicle branching at the onset of panicle elevation in the spring. Treatments were repeated for 3 years. The bluegrass was grown in rows, sprinkler irrigated, and fertilized as needed to maintain high levels of N, P, and K.Some clipping treatments increased seed yields; none decreased yields. Late fall and the onset of panicle development were the two best times for defoliation. Clipping in late fall markedly increased panicle numbers, decreased weight of seed/panicle, and increased seed yield. Clipping at the onset of panicle development in the spring slightly increased panicle numbers and seed yields without materially reducing the weight of seed/panicle.Two clippings produced significantly more Iorage than most single clippings, but not more than one clipping in late fall, apparently because little vegetative growth occurred between late fall and late panicle branching.Defoliation in late fall or early spring prior to secondary panicle branching offers the possibility not only of providing forage but of increasing subsequent seed yield through increased panicle production.

Interrelationship between Meristematic Regions of Developing Inflorescences of Four Cereal Species

A cultivar from each of four cereal species (Avena sativa L., cv. Swan , Hordeum vulgare , L., cv. Clipper , Triticum aestivum L., cv. Gabo, and Secale cereale L., cv. Sohi/i Australian Rye) was grown in controlled environment chambers in a 10-h photoperiod (short days) or 10-h photoperiod supplemented with a 6-h extension by incandescent light. The developmental morphology of the inflorescences was followed to ascertain whether there were any common developmental interrelationships between the species. Inflorescence internode elongation was initiated when the floret initial first appeared, irrespective of whether it occurred on the most advanced lateral spikelet or on the terminal spikelet of the rachis. The glumes (infertile bracts) of the terminal spikelet of the rachis were initiated when the first second-order inflorescence branch appeared, irrespective of whether the second-order inflorescence branch was a floret initial or a lateral spikelet, as in Triticum sp., or an inflorescence (panicle) branch, as in Avena sp. Cessation of the activity of the apical meristem, as measured by primordium formation, was not correlated with any particular stage of floral development but appeared to be due to a lack of nutrients caused by an increasing competitiveness for the available nutrients from the developing spikelets which are situated closer to the vascular system than the apical meristem.

The Effects of X-ray lrradiation on Differentiation and Growth of Rice Plants at the Reproductive Stage.

This investigation was carried out to clarify the effects of X-ray irradiation at reproductive stage on differentiation and development of rice plant. Rice plants at four developmental stages, I. transition stage from vegetative phase to reproduc-tive phase, II. differentiating stage of primary and secondary branches of panicles, III. differentiating stage of spikelet organs and IV. stage of meiosis were acutely exposed to X-rays of 3 kR and 6 kR. Total number of leaves, heading date, Iethal rate, internode length, panicle length, number of tillers, number of primary panicle branches, number of secondary panicle branches, number of spikelets and fertility were measured. An increase of leaves number and delayed heading caused by irradiations of 3 kR and 6 kR at I stage were observed. Frequency of plants having lethal main stem was in sequence of II (=100% lethal)> I>III>IV (=0% lethal) when 6 kR was irradiated. But 3 kR irradiated plants had few lethal main stems. Irradiation of 3 kR at II, III and IV stages more severely suppressed culm elongation than irradiation at I stage. And irradiation at the earlier stage suppressed elongation of the lower internodes. Tillering pattern (number of tillers at each node) of 3 kR irradiated plots was similar to that of 6 kR plots and varied with irradiated stages. The highest node with tiller was elevated by irradiation of later stage.

Components Analysis of Yield Responses to Drought of Sorghum Hybrids

SUMMARYDrought resistance in terms of yield and its components was studied in the field in twenty-one agronomically-adapted high-performance grain sorghum (Sorghum bicolorMoench) hybrids. Resistance was considered to be indicated by a minimal decrease in yield under stress as compared with non-stress conditions. Water stress, imposed by a decreasing amount of stored soil moisture during the growing season, decreased grain yield and number of panicles per unit area, increased the number of grains per panicle, the number of branches per whorl and the number of grains per branch, and decreased the number of whorls per panicle. Thus a compensatory effect was observed in some components for reduction in tillering under stress. Resistant hybrids performed better than susceptible ones under stress by producing a relatively higher number of panicles per unit area, and more grains per panicle branch. Susceptible hybrids performed better than resistant ones under non-stress (irrigated) conditions due to the relatively higher number of panicles per unit area and larger 1000-grain weight. Some of the implications regarding selection for yield performance under drought are discussed.

Studi Keragaman dan Kekerabatan Padi Lokal Asal Kabupaten Siak Berdasarkan Karakter Kualitatif

This study aims to determine the diversity accessions of Siak Regency’s local rice. The study was conducted for six months, from May to October 2018 at Experimental Garden of Agriculture Faculty, Riau University. This study used descriptive qualitative analysis method based on agronomic and morphological characters, as well as characterization activities on 21 local rice accessions. There are 10 morphological characters with low diversity, such as the surface, leaf surface, leaf tongue shape, leaf neck color, leaf ear color, leaf book color, leaf tongue color, grain tip color and the color of the pistil. There are five morphological characters with rather low diversity, such as the presence of lemmapalea hair, the color of stem segments, the color of leaf blades, panicle shaft and vigor. There are five morphological characters with quite high diversity, such as yellowing of leaves, panicle discharge, panicle type, secondary panicle branches and leaf midrib color also three morphological characters with high diversity, such as lemmapalea color, grain tip fur and grain tip fur color. While the agronomic character with a rather low diversity is vigor and there are three characters with quite high diversity, such as the stiffness of stem, yellowing of leaves and panicle discharge.
 
 Keywords: Agronomy, diversity, local rice, morphology.

Studies on Positions in Panicle of Ventral white, Basal white, Milky white like white Core and Milky white kernels, and shapes of White opaque parts in these kernels.

From these studies investigated on positions in panicle of ventral white, basal white, milky white like white core and milky white kernels, we considered on relations between shapes of white opaque parts and positions in panicle of these kernels. Based above consideration, we intend to make clear up the mechanisms of development of these kernels. Results are summarized as follows; 1) Milky white kernels developed at inferior positions in panicle as in Figure 1, and shapes are shown in Figure 2 to 13. White opaque parts of milky white kernels have many different shapes as shown in these figures. 2) Ventral white kernels developed at superior position in panicle as in Figure 1, and shapes are shown in Figure 14 and Figure 15. 3) Milky white like white core kernels developed in high prcentages in the second and the third grains of secondary branch of middle parts in panicle as in Figure 1, and shapes are shown in Figure 16 and Figure 17. 4) Basal white kernels developed in high percentages in the second grain of upper branches in panicle as in Figure 1, and shapes are shown in Figure 18 and Figure 19. 5) We make diagram of developmental process of superior medium and inferior spikelet as Figure 20. This figure is made by the consideration that inferior spikelets develop very slowly and need long days for full ripening. As shown in Figure 20, the most rapidly development time of superior spikelet corresponds to the early development time of medium spikelet (about several days after flowering). As same as above mentioned, the most rapidly development time of medium spikelet corresponds to the middle development time of inferior spikelet (about twenty days after flowering).

Studies on Alkali Decomposition of Rice Kernel : 2. Effects of varieties and some ripening conditions on alkali decomosition of milled white rice

Alkali tests on which the author have reported in the previous paper, were conducted during December 1963 on the milled kernels of 124 rice varieties from 1963 crop. Effects of air temperatures shading and nitrogen application in ripening period were also investigated in relation to alkali digestibility. Most of indica varieties showed their stronger resistibility to alkali than japonica varieties as was already reported by many researchers. Shape of kernel had no clear relation to alkali digestibility in the case of japonica varieties. In indica rice, however, some varieties of big breadth-thickness ratio were less resistant than narrow-grain varieties. Glutinous kernels showed no substantial differences from nonglutinous ones, suggesting that amylose content of kernel had little effect on alkali digestibility of rice kernel. kernels of late season varieties which ripened in low temperature were more digestible rather than early or midseason varieties ripened in hot or warmer season. High temperature (30°C) treatments in ripening periods considerably increased alkali resistance of rice kernels. Shading treatments in the same periods and heavy nitrogen application just prior to heading decreased alkali resistance of kernels. It is considered therefore that environmental conditions which accelerate the development of kernels may increase their alkali resistance through denaturization of synthesizing starch and structural strengthening of endosperm tissues. Green kernels and injured kernels such as milky-white kernels which obsuructed thier ripening by some in jurious causes and kernels collected from kernel-attaching position of inferion strength such as the second kernel from the top on each panicle branch were more digestible as compared with normal kernels and kernels from vigorous positions. Alkali digestibility of milled rice kernel is thought to be mainly dependent upon the nature of endosperm starch being controled by hereditary characters as well as environmental conditions.