Mother Stock Research Articles

A Preliminary Assessment of Sweet Potato Cultivars for Sweet Potato Feathery Mottle Virus (Spfmv).

Four cultivars of sweet potato (Ipomoea batatas) at the Gatton Research Station (Queensland) were screened for sweet potato feathery mottle virus (SPFMV). Both mother stock and field grown material were indexed by grafting to the indicator plant Ipomoea setosa. Within the limitations of our testing procedures, virus was not detected in mother stock of cw. Rojo Blanco (27 grafts), Resisto (20 grafts), LO-323 (22 grafts) and Red Abundance (23 grafts). Four of 35 grafts made with field-grown material were positive suggesting that virus infection of commercial planting material is more likely to occur by infection during field multiplication than from infected mother stock. Virus infection was detected by symptoms on and the presence of flexuous, filamentous particles in sap extracts of I. setosa. The virus was identified as sweet potato feathery mottle potyvirus by serology.

In vitro propagation of Prunus tenella Batsch. cv. ‘Firehill’: control of vitrification; increase of the multiplication rate and growth by chilling

The effects of different factors on the induction, accentuation and reversion of vitrification during the in vitro propagation of Prunus tenella (cultivar ‘Firehill’) were studied. High relative atmospheric humidity (RH) of the culture chamber induced vitrification which could be eliminated by reducing RH from 85 to 45% or by omitting 6-benzyl-aminopurine from the culture medium for one passage. The horizontal positioning of the explants on the culture medium induced vitrification. The use of Lepoivre's basal medium produced less vitrification than that of Murashige and Skoog. After several passages of shoot multiplication, a decline of the multiplication rate of non-vitrified explants occurred. The multiplication rate could be restored by applying chilling treatment (5°C) to the shoots of vitroplants for 30 days. The shoots were rooted in vitro and successfully established ex vitro. A positive after-effect of the cold treatment applied to the shoots in vitro was promotion of the growth of ex vitro established plants. A few months later, all plants flowered and their flowers were identical to those of the original mother stock plant.

ストックのｉｎ ｖｉｔｒｏ器官形成に及ぼす外植体前歴ならびに培地内窒素源組成の影響

ストックの本葉および胚軸からのカルスおよび器官形成(シュート形成)に及ぼす供試植物の栽培条件(光条件•施肥条件)ならびに培地中の窒素組成の影響について検討した.1.葉片培養:(1)光および施肥条件の影響;'銀潮'では遮光処理(75%遮光)によリシュート形成が促進された.また遮光の効果は1/2倍水耕液を施用した区で顕著であった.一方,'雪まつり'では1/4および1/2倍液施用区とも遮光処理によってシュート形成は抑制された.(2)培地の窒素組成の影響;'銀潮'および'雪まつり'とも,アンモニア態窒素無添加区(硝酸態窒素のみ)において高いシュート形成率を示し,NH4++/NO3-比を高めるとシュート形成が抑制される傾向を示した.2.下胚軸培養:(1)光および施肥条件の影響;'リトルゼムイエロー'および'雪まつり'とも,遮光処理によってシュート形成が抑制された.また,外植体当たりのシュート数も遮光処理によって減少した.(2)培地の窒素組成の影響は,'リトルゼムイエロー'および'雪まつり'とも,アンモニア態窒素の添加が,シュート形成率および外植体当たりのシュート数を高める傾向を示した.'リトルゼムイエロー'ではNH4++:NO3-が1:10の培地で,また'雪まつり'ではNH4++:NO3-が1:2の培地でそれぞれ85%と最も高い形成率を示した.3.形成されたシュートは,大部分が水浸状を呈していた.水浸状の葉は,水分を含んで肥大し,その組織では細胞間隙が大きく,維管束や棚状組織の発達が不十分であった.また気孔の分布が一様ではなく,その数も正常葉と比較して少なく,孔辺細胞が表皮細胞より陥没しているものや隆起しているものなどが観察された.

イチゴ親株から子苗への炭そ病菌の伝染と薬剤防除効果

イチゴ親株から子苗への炭そ病菌の伝染と薬剤防除効果

DISEASE INDEXING OF ORNAMENTAL BULB CROPS AND LARGE-SCALE PRODUCTION OF FIRST GENERATION CLEAN MOTHER STOCK THROUGH TISSUE CULTURE

DISEASE INDEXING OF ORNAMENTAL BULB CROPS AND LARGE-SCALE PRODUCTION OF FIRST GENERATION CLEAN MOTHER STOCK THROUGH TISSUE CULTURE

Density of landing aphids on mother stock of strawberry and repellent effects of silver polyethylene film

Density of landing aphids on mother stock of strawberry and repellent effects of silver polyethylene film

Tissue Culture Propagation of African Violets1

Abstract Over 70,000 plants of African violet (Saintpaulia ionantha Wendl.) from over 20 cultivars have been produced by tissue culture in this laboratory. All cultures were started from a single mother stock plant of each cultivar. The ease of the method is enhanced by using premixed inorganic salts which eliminate preparation of stock solutions and the development of media for shoot production and root production that differ only in growth regulators. The plant and flowers appear true-to-type and variegations were not lost or distorted. The plants had the typical flat leafed morphology; none had the unusual upright morphology encountered in some cases by Start and Cumming (1). Only 2 plants had obvious differences in phenotype. These were albinos from ‘Mary D’ and could not survive outside artificial media.

Salt Stock Families in Northwestern Germany: ABSTRACT

In northern Germany there are more than 200 known stocks which are composed of Zechstein salt. Because of favorable geologic conditions, it was possible to reconstruct the historical development of the stocks with the aid of reflection seismic surveys. The development of a single stock appears to have started with an accumulation of salt, the so-called salt-pillow. At a later stage, the overlying strata broke, allowing the diapir to form. In northern Germany, genetic connections between stocks are recognizable. Some of the larger groups of stocks are classified as salt stock families. Such stock families consist of a number of stocks grouped around the genetically oldest which is said to be the stock. The rim synclines of the adjacent stocks become younger as their distances from the center increase. The geological impulse causing the formation of mother stocks is supposed to be partly due to tectonics whereas the subsequent wave-front-like growth of the stock families took place in a purely halokinetic way, i.e., by the movements of under the influence of gravity. The absolute rate of the horizontal wave-front-like flow of the over large distances averages about 0.3 mm./year. End_of_Article - Last_Page 357------------

The Influence of the Mother Stock Conditions on the Qualities, Rooting and Growth of the Cuttings of Tea Varieties

The influence of the conditions of the mother stocks on the qualities, rooting and growth of tea cuttings were examine, using r3 varieties. Significant differences were observed in the qualities, rooting and growth of cuttings among both treatments and varieties, and in the new shoot growth a significant interrelation was observed between treatments and varieties. The state of lateral buds of the slips seemed to have some relations on the new shoot growth.It was thought from the results of this experiment that in nursery test of varieties, rooting ability and vigour of growth should be distinguished, and generally speaking the vigour of growth is to be thought much of.As for mother stock treatments, cuttings from naturally grown (no-pruning) stock which had poorest stem and lowest N-content in leaves and stems showed poorest rooting, and cuttings from stock treated by usual method which had largest stem and highest Ncontent showed best rooting. But the growth of cuttings was best in case of down-pruned stock which had largest leaves.As for varieties, Y 3 which had lowest Ncontent in leaves showed poorest rooting, and such a tendency was observed that the larger the leaves and stems and the lower the N-content in stems, the better the growth of cuttings.The size of leaves seemed to have some relations to the growth of cuttings.Further studies must be done about the relations between the N-content of the slips and the rooting and growth of cuttings in tea.

Diploid-Bud Formation in a Haploid <i>Oryza</i> with Some Remarks on the Behaviour of Nucleolus in Mitosis

1. A fertile diplosporophyte derived from a haplosporophyte by bud-variation was separated as a clone from the mother stock. The root tip cells in the mother stock had 12 chromosomes and those in the fertile diplosporophyte had the doubled chromosome complement.2. There appeared several culms on which the panicles had fei tle grains mixed with some abortive flowers. Some adventitious roots from such culms consisted of haploid cells only, but others had completely diploid cells, and in other cases the root showed the constitution of a sectorial chimera of haploid and diploid tissue in longitudinal rows. A comparison in the sizes of the cells and the thickness of these roots was made and it was concluded that the sizes of the cells in respective tissue are firstly determined by the chromosome complements, but the propagation of the cells in the respective tissue is much influenced by other factors.The ratio of the cell volume of the haploid cells to that of the diploid cells is ca. 1:1.26 which is very near to 3√2, in other words the 2x-cells have about 2 times the volume of 1x-cells.3. As the cause of the bud variation in the present case an over-heating of the water of the culture pot in the sprouting period is suggested. The 2x-sporophytes propagate more rapidly and grow more vigorously than 1x-sporophyte and overhelm the latter. So we can easily see that in nature haplosporophytes produced in some perennial plant, may survive until when the 2x-bud variation appeared among them, an event which proved fatal to the 1x-plants.4. In early period of the mitosis, probably all the chromosomes are attached to the nucleolus either with their special points or with their end. The former are the naked or very thinly covered parts of the chromonemata, and not the surface of the hyalonema (the chromosome matrix). The nucleolar substance is probably concerned in the various stages of the chromosome cycle for all chromosomes, and not limited to particular ones such as the nucleolar or SAT-chromosomes. The latter kinds of chromosomes have longer naked or thinly covered chromonema neck, so that they are attached snore closely to the nucleolus.Here the writer wishes to express her thanks to Prof. K. Fujii for his kind advice in the course of this investigation. Her thanks are also due to the authorities of the Konosu Branch of the Imp. Agric. Exper. Station for the supply of the material.