Corm Growth Research Articles

Effects of lipoxygenase on the corm formation and enlargement in Gladiolus hybridus

To investigate the effects of lipoxygenase (LOX1) on the corm formation and enlargement in Gladiolus hybridus, the field and in vitro researches were conducted to detect the growth and development course, the LOX1 activity, the contents of endogenetic methyl jasmonate (MJ), sucrose, starch and cellulose, as well as LOX isozymes and the expression of its genes in ‘Rose Supreme’ and ‘Advanced Red’. The field investigation showed that the highest activities of LOX1 activity and MJ content in stolons, but not detected in leaves, which were higher in ‘RS’ than in ‘AR’. And the contents of sucrose, starch and cellulose in corm and cormels showed different increase during growth and development of Gladiolus corm. The in vitro investigation showed that the salicylhydroxamic acid (SHAM) treatment caused obviously delayed corm formation, decrease of fresh weight and diameter, and percentage of corm formation; reduced contents of total dissoluble protein, MJ and carbohydrates, and LOX1 activity. Additionally the activity of LOX isozymes became weaker, with two isozyme bands disappeared. In contrast, these physiological and biochemical indexes were increased under MJ treatment. RT-PCR also demonstrated that the expression of LOX1 gene was inhibited under SHAM treatment, induced under MJ treatment. These results suggested that LOX1 might regulate the growth and development of Gladiolus corm through affecting JAs biosynthesis cycles, and then resulting in carbohydrate accumulation. The corm formation could be improved by MJ, but suppressed by SHAM, in which, MJ 0.5 mmol/L was the optimum concentration for promoting corm formation and enlargement in Gladiolus.

Bacillus subtilisFZB24® Affects Flower Quantity and Quality of Saffron (Crocus sativus)

The effect of Bacillus subtilis FZB24 on saffron ( Crocus sativus L.) was studied using saffron corms from Spain and the powdered form of B. SUBTILIS FZB24(R). Corms were soaked in water or in B. subtilis FZB24 spore solution for 15 min before sowing. Some corms were further soil drenched with the spore solution 6, 10 or 14 weeks after sowing. Growth and saffron stigma chemical composition were measured. Compared to untreated controls, application of B. subtilis FZB24 significantly increased leaf length, flowers per corm, weight of the first flower stigma, total stigma biomass; microbe addition also significantly decreased the time required for corms to sprout and the number of shoot sprouts. Compared to the controls, picrocrocin, crocetin and safranal compounds were significantly increased when the plants were soil drenched with the spore solution 14 weeks after sowing; in contrast crocin was highest in untreated controls. Results of this study suggest that application of B. subtilis FZB24 may provide some benefit to saffron growers by speeding corm growth (earlier shoot emergence) and increasing stigma biomass yield by 12 %. While some treatment conditions also increased saffron chemical composition, these were generally not the same treatments that simultaneously improved growth yields and thus, more study is required.

Effects of temperature on the growth of spring ephemerals: Crocus vernus

Spring ephemerals of deciduous forests appear shortly after snow melt and senesce shortly after the overstorey canopy has closed. During this short period, they take advantage of the high light conditions, but also of the low‐temperature regime that favours growth in these species. This better growth at cooler temperatures has been attributed to longer leaf life duration. The objective of this study was to test if temperature effect on growth in spring ephemerals can be explained solely by the leaf life duration, or if there is also a direct temperature effect on the underground organ growth. Crocus vernus (L.) Hill was exposed to two temperature regimes, 12/8 and 18/14°C (day/night), for sequential harvests and to four differential air to soil temperature regimes: 12/12, 12/18, 18/12 and 18/18°C (air/soil temperature). Dry mass, leaf nitrogen, starch concentration and cell size of the new corm were determined. Final dry mass and cell size were higher at the lower temperature regime while leaf lasted longer than at the higher temperature regime. Although both air and soil temperatures had an impact on the different growth parameters measured, the impact of soil temperatures was greater and it also influenced leaf life duration. At higher temperature, corm growth stopped before the first visual sign of leaf senescence, suggesting that corm growth controls leaf life duration in C. vernus rather than the opposite and that crocus growth becomes rapidly sink limited at higher temperatures.

Effect of a multispecies nematode population on the root, corm, and shoot growth of East African Musa genotypes

A study to determine the impact of a multispecies nematode population on the root, corm, and shoot growth of East African Musa genotypes was carried out. Eight genotypes comprising the plantain “Gonja” (Musa AAB group), the dessert banana “Sukali Ndizi” (AAB), the beer banana “Kayinja” (ABB), and five East African Highland bananas (AAA-EA) were assessed at flower emergence of the plant crop. Root damage and plant growth characteristics were assessed on both infected and noninfected plants. This study showed that Radopholus similis and Helicotylenchus multicinctus were recovered in highest numbers from infected mother plants. Significantly (P<0.05) higher shoot and root damage was observed in the infested plot compared to the noninfested plot. The differences in nematode damage observed among the different Musa genotypes confirm the variability in susceptibility to nematodes. Most of the East African Highland bananas and “Gonja” had a significant reduction in root system size. In addition, toppling and lengthening of the period to flower emergence of the plant crop was much more pronounced in these genotypes. In contrast to previous reports, this study indicated that a multispecies nematode infection significantly (P<0.05) reduced shoot and root growth of “Kayinja”. “Sukali Ndizi”, however, was observed to be tolerant to nematode infection as a small reduction in the root system size was associated with a negligible effect on the corm and shoot growth characteristics. Therefore, the percentage reduction in root and shoot growth due to nematode infection is not constant but depends on the plant genotype.

Corm induction and multiplication of Amorphophallus albus in vitro

SummaryAmorphophallus albus, belonging to the family Araceae, has attracted widespread attention due to its considerable economic and medicinal importance. The natural propagation coefficient of A. albus is very low, which limits application of this crop. In vitro corms can be used for propagation of A. albus and have been proved to be superior over in vitro plantlets. To optimise procedures for in vitro corm production and multiplication, the effects of phytohormones, sucrose concentrations and incubation conditions with desirable phytohormone combinations for callus induction, corm formation and corm growth of A. albus were investigated. The results showed that calli were induced at high frequency from petiole segments on Murashige and Skoog medium supplemented with 1.0 mg l–1 naphthaleneacetic acid (NAA) and 1.0 mg l–1 6-benzyladenine (BA). Compact nodular calli were desirable for corm formation, and optimum corm formation was obtained in the presence of 0.5 mg l–1 NAA and 2.0 mg l–1 BA. With this auxin and cytokinin combination, an increase in sucrose concentration from 2% to 6% (w/v) significantly increased the corm formation rate and favoured corm growth, but negative effects occurred at higher sucrose concentrations. By incubating over a range of temperatures from 19°C – 28°C, 22°C produced the largest numbers of corms and highest mean fresh weight of each corm. Short-day (8 h) or long-day (16 h) photoperiods did not affect corm formation and growth significantly, except that corm weight fell under long-day conditions. The multiplication rate of in vitro corms was enhanced by apical meristem wounding. It was possible to store in vitro produced corms at 4°C for as long as 90 d to overcome apical dormancy and accelerate sprouting after planting into soil. This work has established an efficient protocol for multiplication of A. albus through an in vitro corm system.

EFFECT OF LOW TEMPERATURE AND CHITOSAN ON DORMANCY BREAKING AND GROWTH OF YOUNG CORMS OF THREE ARISAEMA SPECIES

EFFECT OF LOW TEMPERATURE AND CHITOSAN ON DORMANCY BREAKING AND GROWTH OF YOUNG CORMS OF THREE ARISAEMA SPECIES

Plant Growth Regulators Affect the Development of Both Corms and Cormels in Gladiolus

The effects of BA, ethephon, and GA3 on freshly harvested cormels of three cultivars of Gladiolus sp. were studied for 3 years. The treatment with 400 mg·L-1 ethephon significantly reduced the dormancy period by 17.5 days as compared to control, while BA and GA3 were found to be less effective. Among all treatments, ethepon at 400 mg·L-1 was found to be the most effective in altering the days to sprout, sprouting percentage, corm size and production and development of cormels. While GA3 at 100 mg·L-1 increased growth of corms and cormels, BA at 25 mg·L-1 increased growth of corms and cormels. BA at 25 mg·L-1 only influenced the sprouting percentage of cormels. Along with reducing the dormancy period, the plant growth regulators stimulated growth and development of corms and cormels. Chemical names used: benzyladenine (BA); 2-chloroethylphosphonic acid (ethephon); gibberellic acid (GA3).

The Growth of Saffron (Crocus sativus L.) in Aeroponics and Hydroponics

ABSTRACT The development of saffron (Crocus sativus L.) plants and the production of commercial saffron and saffron constituents were compared in three culture systems: aeroponics, hydroponics, and soil. On a dry weight, but not fresh weight basis, corm growth was increased in aeroponics and hydroponics as compared with growth in soil. Root length in aeroponics and hydroponics was reduced as compared with root length in soil, but shoot development was not significantly affected. Flowering was poor in all three culture systems, probably due to the small-sized (2.6 cm) bulbs used in propagating the plants. The production of stigmas and the concentration of the main constituents of saffron in the stigmas was similar in all three culture systems, suggesting saffron bulbs grown aeroponically and hydroponically may be used as a practical and renewable source of pharmacological compounds extracted from saffron.

Induction and characterization of in vitro corms of diploid-taro

When in vitro plantlets were cultured in Murashige and Skoog liquid medium supplemented with 8–10% sucrose and 22–44 μM 6-benzylaminopurine, all of the stem explants formed corms. 170–850 μM paclobutrazol increased corm formation, whereas 1700 μM paclobutrazol inhibited corm development. Inclusion of 66 μM 6-benzylaminopurine in 170 μM paclobutrazol treatment resulted in smaller corms, and bigger corms formed in the combination of 1700 μM paclobutrazol and 66 μM 6-benzylaminopurine. No corms formed in 63–630 μM cycocel treatments. In vitro corm growth was also affected by the culture methods. Deep-layer agitated culture yielded corms of up to 2.03 g, with an average fresh weight of 0.7 g, 40 days after induction. In thin layer cultures, corms were up to 1.87 g, with an average fresh weight of 0.5 g. SDS-PAGE analysis of water-soluble proteins revealed changes of polypeptides with corm growth. Compared to smaller ones, corms over 0.2 g had higher dry matter, carbohydrate and anthocyanin content. These corms had a 99–100% survival rate upon transplanting directly to soil after storage at 4 °C for 10 months. This study indicates that the most economic production method of diploid taro seed corm is by thin-layer liquid culture in Murashige and Skoog medium supplemented with 22–44 μM benzylaminopurine and 8–10% sucrose for 6 weeks. The formed corms can be stored at 4 °C up to 10 months and transplanted directly into soil without acclimatization.

Nutrition of container‐grown freesias

As limited information is available on the nutrition of freesias an experiment was carried out to examine the influence of nutrients on foliage and corm growth, and flowering of container‐grown plants. The experiment ran for 10 months using seedlings grown in a peat:sand (3:1,v:v) medium with combinations of varying levels of nitrogen (N), phosphorus (P), potassium (K), and lime. Nitrogen fertilization had a significant effect on many aspects of flowering and growth while the response to P was similar except for a lack of influence on spike production. Fertilization of 600–800 g N m‐3 and at least 200 g P m‐3 are recommended for strong leaf and corm growth with good flowering. There were few significant responses to added K, except in early foliage growth, while liming increased foliage development. High flowering, leaf, and corm growth should be achieved with a media pH of 5.9 and foliar nutrients of 2.2–2.3% N, 0.25–0.30% P, 4.0–4.5% K, 0.65–0.80% calcium (Ca) and 0.20–0.25% magnesium (Mg).

Underground plant movement III. The corm of Sauromatum guttatum (Wall.) Schott (Araceae)

Summary Underground movement in some Araceae shows that in cormous plants, both root contraction and shoot growth are important factors. In depth regulation, two kinds of movement can be distinguished. To secure an underground position it is necessary to compensate the upward growth of vertical corms. Thus, in Sauromatum , either a defined position is maintained, or small downward movement of adult corms occurs. Greater movements are necessary to reach an ecologically useful position. The observation of Sauromatum seedlings makes clear that at this stage of plant life the force involved in downward movement is relatively low. The corm is very small and, on turning, a channel effect can occur. In Arum and Arisarum , even adult corms show greater movement. This occurs when the normally horizontally growing corm is re-oriented into the direction of contractile root activity. This produces summation of both types of movement. Simultaneous occurence of root activity and corm growth is not possible in the vertical position of adult Sauromatum corms. However, lateral buds are normally positioned at an angle to the mother corm initially, and move in a way similar to that of Arum .

A fatal growth pattern and ways suspected of postponing death: corm dynamics in the perennial herb Corydalis cava

The forest herb Corydalis cava is the only known species with a corm where tissue is added annually as a layer on the outside, and where the older central parts rot away, i.e. the corm becomes an expanding sphere. This growth pattern creates energetic problems for ageing plants. However, older corms change their shape in a way that saves biomass. Growth of corm with age was here modelled introducing different corm traits saving mass and thus postponing death. The largest corm in the study patch had a volume of 60 ml. If such a corm had remained a solid sphere, its age would be estimated to be 8.3 years. In reality, 4 year old corms became hollow and later an opening appeared in their basal part. In addition, corms ≥ 7 years became more conical. A conical corm with a volume of 60 ml was estimated to be 15.9 years old. Volume and shape of corm thus made it possible to age individual plants. The age structure of the plants in the study patch was described and discussed in relation to the overall dynamics of the metapopulation. The patch consisted of a few strong age classes (from 5 to 7 years old). Any recruiting juvenile age classes were almost completely missing.

A fatal growth pattern and ways suspected of postponing death: corm dynamics in the perennial herb Corydalis cava

The forest herb Corydalis cava is the only known species with a corm where tissue is added annually as a layer on the outside, and where the older central parts rot away, i.e. the corm becomes an expanding sphere. This growth pattern creates energetic problems for ageing plants. However, older corms change their shape in a way that saves biomass. Growth of corm with age was here modelled introducing different corm traits saving mass and thus postponing death. The largest corm in the study patch had a volume of 60 ml. If such a corm had remained a solid sphere, its age would be estimated to be 8.3 years. In reality, 4 year old corms became hollow and later an opening appeared in their basal part. In addition, corms ≥ 7 years became more conical. A conical corm with a volume of 60 ml was estimated to be 15.9 years old. Volume and shape of corm thus made it possible to age individual plants. The age structure of the plants in the study patch was described and discussed in relation to the overall dynamics of the metapopulation. The patch consisted of a few strong age classes (from 5 to 7 years old). Any recruiting juvenile age classes were almost completely missing.

サトイモ培養球茎の生育特性の品種間差異と早熟栽培への利用

サトイモ品種群の代表的な5品種•系統を供試し,その培養球茎株と慣行球茎株の特性を比較した。また,'石川早生'の培養球茎を用いたハウス, トンネルによる早熟栽培における生育特性を調査し, 培養球茎を利用した栽培の実用化について検討した。1.各品種, 系統ともに培養球茎株は慣行球茎株に比べて地上部の生育は劣るが地下部球茎の肥大は良く,植物体全体に占める球茎の割合が大であった。2.子芋利用品種'烏播', '土垂', '早生小蓮葉芋', '石川早生'では子芋, 孫芋の着生数が増加して1個当たりの重量は小さくなる傾向があった。3.親芋利用型の変異系統では培養球茎株は親芋の肥大が良かった。子芋利用品種では親芋は小さくなり,利用部位である子芋, 孫芋の割合が大きかった。4.'石川早生'ではハウス栽培, トンネル栽培でも培養球茎株の生育特性は露地栽培と同様の傾向が認められた。5.培養球茎株は慣行球茎株に比べ地上部の枯れ込みが早くから開始され, 子芋, 孫芋の肥大は早くなることが認められた。6.早生品種を用いたハウス, トンネルによる早掘り栽培で培養球茎を直接利用した栽培の実用化の可能性が示された。

Precocious gladiolus corm formation in liquid shake cultures

Conditions were defined for precocious differentiation and improved growth of corms at the base of gladiolus shoots. Shoots were derived from explants cultured on agar solidified media, and corm regeneration was obtained in subsequent liquid shake cultures. Benzyladenine (BA), at 10-7 M, was found to have a stimulating effect mainly when provided to the shoots prior to manifestation of corm growth. Paclobutrazol and sucrose promoted corm formation when supplemented to the liquid media. Paclobutrazol, at 10 mg l-1, shifted assimilate allocation towards the growing corm. A differential promotion of corm development by sucrose was not observed, and the concentration of sucrose at which the sugar demand for maximal shoot and corm growth is satisfied (60 g l-1) was unaltered by the presence of paclobutrazol. The rate of corm growth on shoots cultured in a liquid medium supplemented with paclobutrazol and a saturating sucrose concentration, was a function of the length of the shoot's leaf blades, and was similar in light and in dark.

Photothermal effects on corm and flower development in Anemone coronaria L.

The effect of photoperiod, thermoperiod and corm characteristics on corm and flower development in Anemone coronaria L. were studied under controlled conditions using a hybrid cultivar (‘Hollandia’ × Israeli wild type) possessing summer dormancy inducible by long days (LD) and/or high temperatures. Corm differentiation did not require photothermal induction and occurred very early in seedling development. The size of the corm at the end of the growth cycle (dormancy onset) was the net result of the differential effects of day length and temperature on its growth rate and growth period. LD of 16 h promoted corm growth rate compared with short days (SD) of 8 h, but high temperature and LD reduced its final size owing to the earlier induction of dormancy. A direct relationship existed between the phenological state that the plants attained in the field at the time of corm harvest and the responsiveness to subsequent dormancy induction by LD. The later the corms became dormant in the field and the larger their size, the less responsive were the plants to subsequent dormancy induction. However, the phenological state and the weight of the corms did not affect the time to flowering or the proportion of the plants that reached flowering under LD (77%) or SD (95%) conditions. Larger corms produced more shoots and flowers per corm, but the number of flowers produced per shoot was unaffected by initial corm weight. Flower size (scape length and perianth diameter) was reduced by high temperature under both LD and SD, but flowers were larger under LD. Smaller corms tended to produce large flowers.

In vitro propagation of Gladiolus flanaganii

The successful in vitro propagation of Gladiolus flanaganii, a rare summer-flowering species from the Natal Drakensberg is described. Kinetin was able to stimulate axillary bud growth and ensured that the corms did not enter dormancy during the tissue culture stage. The incorporation of NAA in the hardening-off medium had no deleterious effect on corm growth and stimulated root production.

生育温度がグラジオラス及びオキザリス (&lt;i&gt;Oxalis bowieana&lt;/i&gt; Lodd.) のけん引根及び子球の形成&amp;bull;肥大に及ぼす影響

1. Day/night temperatures of 30/24°C markedly promoted the growth of aboveground parts in both gladiolus and oxalis (Oxalis bowieana Lodd.), and especially in oxalis, continued unfolding of leaves and development of axillary inflorescences were without formation of daughter bulbs. Low temperatures of 17/12°C, however, depressed the growth of aboveground parts, and especially in oxalis, there occurred no increase in the number of leaves and leaf area and no development of inflorescences. While at 24/17°C, the growth was much favoured in both of the aboveground parts and the underground parts. Moreover, when root temperature was controlled independent of air temperature in gladiolus, the growth of aboveground parts was better at lower root temperatures, and such effect of root temperature was greater at the medium than high air temperatures.2. In both gladiolus and oxalis, the number of contractile roots was not affected by air and root temperatures. The elongation and thickening growth of contractile roots, however, were promoted at lower temperatures. The maximal weight of contractile roots and its decrease following contraction were greater in order of low, medium, and high temperatures. Especially in oxalis, there occurred no thickening growth and in gladiolus, not a few contractile roots deteriorated, at the high temperatures of 30/24°C. The formation and thickening growth of daughter corm or bulbs were depressed at higher temperatures, and in oxalis no daughter bulbs were produced. The above-mentioned effects of temperature seemed to be mostly due to the root temperature, at least in gladiolus, according to the experiment in which air and root temperatures were controlled separately.3. The contribution rates of contractile root(s) to the thickining growth of daughter corm or bulbs were calculated as in the previous report (2). In oxalis, the values as high as 56-59% were obtained and they did not vary with growing temperatures. While in gladiolus, they were markedly low and differed with growing temperatures, being comparatively higher at lower temperatures.

グラジオラス及びオキザリス (&lt;i&gt;Oxalis bowieana&lt;/i&gt; Lodd.) におけるけん引根の肥大&amp;bull;収縮と子球の肥大について

グラジオラス及びオキザリス (&lt;i&gt;Oxalis bowieana&lt;/i&gt; Lodd.) におけるけん引根の肥大&amp;bull;収縮と子球の肥大について

グラジオラス及びオキザリスにおける母球の植え付け深さがけん引根及び子球の形成&amp;bull;肥大に及ぼす影響

グラジオラス及びオキザリスにおける母球の植え付け深さがけん引根及び子球の形成&amp;bull;肥大に及ぼす影響