Basal Florets Research Articles

Effect of modified atmosphere packaging and storage duration on keeping quality of gladiolus spikes

Gladiolus has elegant spikes with bright florets and good keeping quality. The storage of spikes duringproduction period will be beneficial for the farmers during low production period. Thus, the present study was planned to investigate the effect of long term modified atmosphere storage on gladiolus spikes. The spikes of gladiolus cv. Alexander the Great, harvested at tight bud stage, were treated with sucrose (20%) + aluminum sulphate (300 ppm) for 20 h followed by sealing in LDPE and PP sleeves (25 μm) with and without perforations and stored vertically at 3–4°C for 0, 6, 12 and 18 days. After storage, vase-life was evaluated. The basal florets opened in all sleeves after 18 days of storage. Increase in storage duration hastened the opening of basal florets, whereas packaging did not affect significantly. Vase-life, opening of florets (%), floret diameter and physiological weight declined with increase in storage duration.

Studies on the effect of foliar application of calcium on post-harvest, corm and cormel production in gladiolus CV. summer sunshine

The experiment was conducted during the year 2011–2013 in Mondouri Horticultural research farm, BCKVV, Mohanpur, West Bengal to study the role of calcium and to identify its effective source and application time on the post-harvest, corm and cormel parameters of gladiolus with foliar application of calcium nitrate and calcium carbonate at different days (3–4, 6 leaf and spike emergence) after plantingand was conducted in Randomized Block Design with three replications. Analysis of variance study indicated that most of the treatments differed significantly among themselves except for days taken for basal floret open, no of corms per plot, corm weight and no of cormels per corm in both the years. The results obtained revealed that foliar spray of calcium favored most of the post-harvest, corm and cormel characters. Calcium nitrate was found superior to calcium carbonate in promoting various post-harvest, corm and cormelcharacters under study. Spraying of calcium nitrate at 6 leaves stage and spike emergence stage to gladiolus plant was most effective to influence the post-harvest, corm and cormelparameters and was found on par with calcium nitrate 300 ppm at 6 leaves stage for maximum characters like vase life, cumulative water uptake, days to incipient senescence, fresh weight of spike, days to senescence, corm diameter, corm thickness and cormel weight per plot.

English

The experiment was carried out to investigate the effect of different chemical solutions (C1= sucrose (20%) + [Al2 (SO4)3 .-16H2O 300 ppm], C2= sucrose (20%) + [Al2 (SO4)3 .-16H2O] 300 ppm + GA3 50 ppm and C3= Control (Distilled water)) and five storage durations viz., (S0 = 0 days, S1 = 7 days, S2 = 14 days, S3 = 21 days and S4 = 28 days) on keeping quality of cut spikes of gladiolus ‘White Prosperity’. The results showed that chemical solutions as well as storage durations significantly influenced the studied parameters. Among the chemical solutions, C2 was significantly superior with regard to days to open basal floret, vase life, number of florets opened, floret size, longevity of open florets and fresh weight gain/loss, while the lowest values of these parameters were recorded in control treatment. Similarly, shorter storage durations of 0 days (S0) recorded higher vase life, longevity of open floret and total water absorption, while days to open the basal floret and floret size were superior in S3 storage and rest of the parameters were significantly higher in S2 storage duration. The spikes stored in S4 treatment did not open either pulsed with chemical solutions or in control. Key words: Aluminium sulphate, gladiolus, gibberellic acid, sucrose, storage duration, quality parameters.

Studies on vase life of tinted spikes of gladiolus cultivar white prosperity

An investigation was undertaken to study the vase life of tinted spikes of gladiolus cultivar. White prosperity harvested at different stages. The experiment comprised of two factors of which the first one was spikes treated with eight food dyes with 5% concentration and time of immersion for two hours and the second one was various stages of harvest. The results revealed that spikes harvested at stage 1(1-2 basal florets show colour) had a higher vase life of 8.16 days, maximum time of 8.56 days to fully loose colour after tinting, lowest mean transpirational loss of 29.17 g. spike-1, highest mean diameter of florets ( 9.21 cm), least decrease of 4.52 g/100g mean percentage of lipids and least decrease of 12.59 g/100g mean percentage of proteins. Benefit cost ratio of tinting the spikes with Lemon yellow, Violet and Orange red was 1.34 while with Kesar yellow, Kalakatta, Blue and Apple green was 1.29. Thus it can be concluded that for tinting the spikes of gladiolus cv. White Prosperity, with greater vase life harvesting the spikes at stage 1(1-2 basal florets show colour) was found to be optimum.

Optimization of stage of harvest of spikes of gladiolus cultivar White prosperity for tinting

A study was undertaken to optimize the stage of harvesting the spikes of gladiolus cultivar White Prosperity for tinting with food dyes. The experiment comprised of two factors of which the first one was eight food dyes with 5% and time of immersion for two hours and the second one was various stages of harvest. In gladiolus cv. White Prosperity, the spikes harvested at stage 1(1-2 basal florets show colour) had a higher vase life of 8.16 days, least wilting percentage of 0, 5.46, and 30.01% on fourth fifth and sixth day respectively. It can be concluded that for tinting the spikes gladiolus cv. White Prosperity, stage 1(1-2 basal florets show colour) was found to be optimum.

Variability studies in gladiolus

In the study of genetic variability, heritability and genetic advance in gladiolus, wide differences were found in mean performance of genotypes for almost all the characters. Variety Adagio possessed maximum plant height with highest number and width of leaves while Friendship White had the shortest height. Variety Jessica was the earliest in emergence of flower spike, showing colour of basal floret and opening of basal floret. Variety White Prosperity possessed maximum spike length, rachis length and number of florets with highest bloom life. Maximum range of variation was observed for length of spike whereas the minimum was recorded for spike diameter. Characters such as weight of corm exhibited maximum co-efficient of variation (GCV and PCV) coupled with high heritability and genetic advance as percentage of mean followed by number of florets per spike, diameter of corm, rachis length and difference between two florets which could be relied upon for effective selection and crop improvement in gladiolus.

Performance of Gladiolus Cultivars under Sub-Humid Southern Plains of Rajasthan

An investigation was carried out during October 2011 - May 2012 to evaluate performance of 15 cultivars of gladiolus for cut-flower, corm and cormel production. Cultivar 'IIHR-G-12' gave maximum plant height (108.32cm), spike length (76.43cm), rachis length (58.27cm), number of florets per spike (14.90), number of florets open at a time (3.63), longevity of florets (3.39 days), vase life of spike (14.20 days), number of spikes per plant (2.50), field durability of spike (16.20 days), flowering duration (38.20 days), number of corms per plant (2.55), corm diameter (6.13cm) and fresh weight of cormels per plant (29.42g); while, cv. 'Gunjan' gave largest floret diameter (10.39cm) and cormels per plants (60.76). Earliness in heading (65.87 days), spike emergence (70.43 days), first floret showing colour (82.93 days) and basal floret opening (85.60 days) were observed in cv. 'IIHR-G-12'. Significantly high corm fresh weight (70.24g) and leaf width (3.28cm) were noticed in cv. 'Pusa Kiran'. However, largest cormel diameter (1.91cm) was seen in cv. 'Delhi Pink', maximum number of tillers per plant in cv. 'Punjab Dawn', whereas, number of leaves plant-1 (9.60) and leaf length (40.41cm) were recorded in cv. 'Dhanvantari'. Among the cultivars tested, cv. IIHR-G-12 was found to be the best for significantly high spike yield (4.17 lakh), corm yield (4.25 lakh) and cormel yield (49.03q) ha-1.

Floral morphogenesis and proliferation in Poa labillardieri (Poaceae)

Inflorescence and spikelet development in Poa labillardieri Steud. were investigated by scanning electron microscopy. Thirteen developmental stages were described in detail, starting with the vegetative shoot apex which was shown to be of the short type (stage zero), followed by a conversion from vegetative to floral meristem at Stage 1 and ending at Stage 12, with a mature panicle consisting of a variable number of florets at anthesis within each spikelet. The occurrence of short-type vegetative apices in this perennial grass adds further support to the view that there is no correlation between life span and the apex type. The branches of the P. labillardieri panicle are formed in acropetal succession; however, it is the upper branches that first bear rudiments of the spikelets, starting at the tip of the branches. In contrast differentiation of florets within each spikelet occurs in acropetal succession, so that the basal floret is farthest advanced and each successively upper floret less advanced. P. labillardieri occasionally produces inflorescences containing spikelets in which some or all of the florets are replaced by a plantlet that is structurally similar to a vegetative tiller. Proliferous development ranged from a situation where all florets were converted to vegetative propagules that can be detached and rooted readily in soil, to cases where proliferation extended only as far as an enlargement of the lemma, with either functional or non-functional sexual organs in its axil. Under greenhouse conditions, there was a shift from occasional cases of partially proliferating spikelets that occur in the wild to complete vigorous proliferation stimulated by unknown factor(s). Departure from the normal sexual pattern took place from early Stage 5 (initiation of spikelet primordial) to late Stage 6 (differentiation of florets).

Breeding potential of durum wheat landraces from Jordan

A Jordanian durum wheat collection consisting of 132 landraces was evaluated in an arid and a semiarid location for 21 morphological and developmental traits. Phenotypic diversity indices (H') were calculated for traits, districts, and regions of collection. Average diversity for Jordan was 0.675 ± 0.05. The pattern of variation of individual traits varied among districts and among regions. Polymorphism was high for waxiness (H' = 0.95), lodging resistance (0.91), stem solidness (0.86), glume color (0.80), and fertility of the basal floret (0.80). However, H' estimates were relatively low for early growth vigor (0.49), seed color (0.44) and juvenile growth habit (0.19). A clinal pattern was observed for resistance to common bunt, Tillelia foetiila (H' = 0.73), stripe rust, Puccinia striiformis (H' = 0.74), and powdery mildew, Erysiphe graminis f.sp. tritici (H' = 0.63). The frequency of resistant entries increased from the xeric south to the mesic north. Average diversity for developmental traits (i.e., days to heading, days to maturity, and filling period) was significantly higher in the semiarid (H'= 0.847 ± 0.05) than in the arid (H'= 0.658 ± 0.12) location. A hierarchical analysis of variance indicated that significant differences for H' estimates existed among regions and among districts within regions of collection. Landraces and districts with high frequency of agronom-ically desirable traits have been identified.

Breeding potential of durum wheat landraces from Jordan I. Phenotypic diversity

A Jordanian durum wheat collection consisting of 132 landraces was evaluated in an arid and a semiarid location for 21 morphological and developmental traits. Phenotypic diversity indices (H) were calculated for traits, districts, and regions of collection. Average diversity for Jordan was 0.675 ± 0.05. The pattern of variation of individual traits varied among districts and among regions. Polymorphism was high for waxiness (H’= 0.95), lodging resistance (0.91), stem solidness (0.86), glume color (0.80), and fertility of the basal floret (0.80). However, H’ estimates were relatively low for early growth vigor (0.49), seed color (0.44) and juvenile growth habit (0.19). A clinal pattern was observed for resistance to common bunt, Tillelia foetiila (H’= 0.73), stripe rust, Puccinia striiformis (H’= 0.74), and powdery mildew, Erysiphe graminis f.sp. tritici (H’= 0.63). The frequency of resistant entries increased from the xeric south to the mesic north. Average diversity for developmental traits (i.e., days to heading, days to maturity, and filling period) was significantly higher in the semiarid (H= 0.847 ± 0.05) than in the arid (H= 0.658 ± 0.12) location. A hierarchical analysis of variance indicated that significant differences for H’ estimates existed among regions and among districts within regions of collection. Landraces and districts with high frequency of agronomically desirable traits have been identified.

Qualitative trait variation in Tef [Eragrostis tef (Zucc.) Trotter] germplasm from Western and Southern Ethiopia

Three thousand tef [Eragrostis tef (Zucc.) Trotter] single panicle derived lines representing 60 populations from western and southern parts of Ethiopia were characterized for panicle form, pigmentation of lemma and anther, caryopsis color, number of main shoot culm internodes, and counts of florets/spikelet at the basal, middle and apical parts of the panicle at Debre Zeit Agricultural Research Center during the 1999 main season. The objectives were to assess the diversity patterns of the germplasm with respect to regions and altitude zones. Among the eight characters, high Shannon-Weaver diversity indices (H’) were noted for anther color (0.71) and number of apical spikelet florets (0.68), and the lowest occurred for panicle form (0.40). Monomorphism (H’ = 0.00) was observed for panicle form, lemma color and number of middle spikelet florets each in three different populations. The overall diversity index for all populations was 0.53. In the analysis of variance of H’ estimates, substantial (p <0.05) regional differences were obtained for lemma color, number of culm internodes, and counts of middle and basal spikelet florets. Clinal variation was significant for panicle form, lemma and seed color, and for the overall mean of traits. Over all traits, mean H’ values declined from 0.60 to 0.46 with an increase in the altitude zone of origin from below 1800 to over 2400 meters above sea level. Overall, the study showed substantial diversity in the test tef germplasm.

Loss of Kernel Set Due to Water Deficit and Shade in Maize

To advance our understanding of the underlying processes by which kernel set is regulated in maize (Zea mays L.), leaf photosynthesis, sugars, starch, abscisic acid (ABA), and cytokinin were quantified in plants subjected to water deficit and shade, imposed for 5 d at the pre‐pollination and early post‐pollination stages. Both water and light deprivation, at both stages, decreased kernel set primarily in apical ear regions. Treatments decreased leaf photosynthesis similarly; however, sugar concentrations in reproductive tissues increased in water deficit while they decreased 20 to 50% in shade. During treatments, nonstructural carbohydrate accumulation was nearly halted in both apical and basal florets at the pre‐pollination stage, whereas it was decreased to a greater extent in apical than basal endosperm/nucellus at the post‐pollination stage. Both water deficit and shade increased ABA concentrations in reproductive tissues, but only at the post‐pollination stage was ABA greater in apical than basal ear zones, thus corresponding to effects on kernel set. Treatments did not consistently alter zeatin‐like cytokinin concentrations. We conclude that photosynthate flux and ABA are components of a regulatory system by which water and light deprivation affect kernel set at the post‐pollination stage, while additional factors may underlie effects at the pre‐pollination stage.

Carbohydrate traffic during opening of gladiolus fiorets

SummaryThe opening of gladiolus florets was accompanied by a substantial increase in fresh and dry weight and carbohydrate content of the perianth. The principal soluble carbohydrate was fructose, with substantially lower concentrations of glucose and sucrose. Although stored carbohydrate, apparently starch, disappeared during floret opening, its contribution to the total carbohydrate content of the open flower was minor. Removal of basal florets from the freshcut spike substantially reduced the dry weight of the opening upper young buds. During development of the inflorescence it appears that there is a transfer of carbohydrate from the senescing lower florets to those developing acropetally.

Variation in photoperiod response of different isogenic lines of wild oats (Avena fatua)

For wild oats, persistence characters such as seed production and seed dormancy may be affected by genetic variation and several environmental factors during the development of the parental plant. However, the effect of varying photoperiods on such characters is unclear. Previous studies have concentrated on natural populations and have not studied the genetic variability within the population. Consequently, a study was conducted to examine how photoperiod (10, 12, 14, 16, and 18 h at 20 C) influenced the persistence of different members of a synthetic population of wild oats. This synthetic population consisted of several isogenic lines with differing degrees of seed dormancy that originated from one region in North America. All lines were photoperiod sensitive, quantitative long day plants, with an increase in time to maturity for all lines (about 78 to 213 d) when photoperiod was reduced from 18 to 10 h. The lines within this synthetic population (with the exception of one, M73) showed a similar degree of photoperiod sensitivity. This may be expected, as the lines are from one region with the same photoperiod environment. It could be concluded that such a photoperiod sensitivity is a beneficial character that has allowed persistence of these lines in this region. When photoperiod was reduced from 18 to 10 h, plants produced fewer seeds (about 141 to 61 primary seeds per plant) with a higher degree of seed dormancy (about 88 to 54% germination in 10−4M gibberellic acid; GA3). The reduced seed production under the shortest photoperiod (10 h) was due to poor panicle exsertion, which resulted in poor development of basal florets. There was no consistent relationship between photoperiod and other plant characters such as tiller production, caryopsis weight, and water content. However, significant relationships were found between seed dormancy characters and other plant characters such as maturity time, caryopsis weight, and water content under certain photoperiod treatments.

Floral Morphology and Development of `Sharpblue' Southern Highbush Blueberry in Louisiana

Floral morphology and differentiation of `Sharpblue' southern highbush blueberry (Vaccinium corymbosum L.) were studied under natural growing conditions. There was no rest period during floral development of `Sharpblue' blueberry in Louisiana. Basal florets were already present within a racemic inflorescence in early September. All floral and reproductive organs were clearly visible in early December. Microspores and pollen grains were observed in mid- and late-January, respectively. Megasporocytes, two-cell, four-cell, and seven-cell embryo sacs were found to be simultaneously present in developing ovules in late January, suggesting that megasporogenesis and megagametogenesis in `Sharpblue' blueberry are asynchronous.

Extension of Postharvest Keeping Time of Antirrhinum majus L. Cut Flowers with Hydrogen Peroxide

Three percent hydrogen peroxide (H2O2) was diluted with deionized water (dH2O) to 0.75%, 0.38%, 0.19%, 0.09%, or 0.05% H2O2 plus 1.5% sucrose for use in evaluation of Antirrhinum majus L. (snapdragon) cut flowers. Other vase solutions used as controls included; 300 ppm 8-hydroxyquinoline citrate (8-HQC) plus 1.5% sucrose; dH2O plus 1.5% sucrose; and dH2O. A completely random design with 7 replicationss was used. Flowering stems of three commercial inbreds and one F1 hybrid of snapdragon were cut when the first five basal florets opened. Each stem was placed in an individual glass bottle containing one of the eight different treatments. Flowering stems were discarded when 50% of the open florets wilted, turned brown, or dried. Postharvest life was determined as the number of days from stem cutting to discard. Addition of H2O2 to vase solutions at rates of 0.19 and 0.09% resulted in postharvest life not different from that obtained with 8-HQC plus sucrose. Hydrogen peroxide plus sucrose extended postharvest life of snapdragon cut flowers 6 to 8 days over dH2O and 5 to 7 days over dH2O plus 1.5% sucrose.

Number of Open Florets on a Flowering Stem Influences Postharvest Life of Antirrhinum majus L.

Flowering stems from three commercial inbreds and their F1 hybrids of Antirrhinum majus L. were cut when the first eight basal florets opened. Tops of the stems were removed above the eighth floret and florets were removed leaving two, four, six, or eight open florets on a stem. A completely random design with 10 replications was used. Flowering stems were placed in plastic storage containers 35 × 23 × 14 cm (L × W × H) with 2.5 L deionized water for postharvest evaluation. Evaluation took place under continuous cool-white fluorescent light (9 μmol·m–2·s–1) at 24°C Postharvest life was determined as the number of days from cutting to discard when 50% of the open florets on a flowering stem wilted, turned brown, or dried. Results showed postharvest life increased as the number of open florets on a stem decreased. Mean postharvest life increased as much as 4.7 days when only two florets remained on a stem. These results indicate a direct relationship between number of florets on a cut flower stem and postharvest life.

Hereditary symbiosis in the grass genus Danthonia

summaryHereditary symbiosis between the systemic, clavicipitaceous fungus Atkinsonella hypoxylon (Pk.) Diehl and five taxa of eastern North American Danthonia (Poaceae) was investigated by cultural and histological techniques. Many species of Danthonia, including D. alleni (or D. spicata var. alleni), D. compressa, D. epilis, D. serirea, and D, spicata produce both terminal panicles of wind‐pollinated florets and obligately self‐pollinated cleistogamous florets in the lower leaf axils, unlike most grasses. Terminal florets are aborted by infection while the basal florets produce viable, infected seeds (caryopses). The fungus grew out of surface‐sterilized cleistogamous seeds and seedlings at high frequency in progenies from infected plants but not from uninfected plants. Infection of seeds from terminal panicles from apparently healthy plants was lacking in 11 of 13 population samples from all taxa and was infrequent in two other populations. Growth chamber tests indicated that germination rates of infected and uninfected seeds of D. epilis were similar. Microscopic observations of sections of seeds and seedlings revealed that the fungus occurred epiphytically on meristems, in leaf axils, and on leaf primordia. Because infected plants are partially fertile, the fungus may be repeatedly transmitted for many generations via self‐fertilized cleistogamous seeds. The basal, and often subterranean, location of cleistogamous seeds may facilitate high infection frequencies in those Danthomia populations where cleistogamous seedling establishment predominates.

The Effect of Temperature on Seed Set and Seed Development in Detached Spikelets of Perennial Ryegrass (Lolium perenne L.)

In perennial ryegrass seed yield is low. Pollination, fertilization and early stages of seed development are critical periods for the realization of the yield potential. As intact plants are difficult to handle, we used detached spikelets to study effects of temperature and genotype on seed set and seed development.Plants of four cultivars were grown in pots. Just prior to flowering, spikelets were detached from the ears and put on water. After pollination, various spikelets of each plant were placed at different temperatures (14/14, 17/12 or 20/15°C). Seven days after pollination the percentage seed set and the length of the developing seeds (caryopses) were assessed. Only florets in the four basal positions were used.For each cultivar an analysis of variance for unbalanced data was carried out. There were highly significant difference among genotypes for seed set and caryopsis length. There was no evidence for genotypic variation for tolerance to low temperatures. Neither temperature nor floret position had an effect on seed set. The caryopsis length, however, increased with increasing temperature and basal florets produced longer caryopses than distal florets. The detached spikelets proved to be a useful experimental tool.

Hypogynous bristles and scales in basal florets in amphicarpous Schoenoplectus species (Cyperaceae)

A perianth of bristles is known in both aerial and basal florets of the amphicarpous sedge Eleocharis minima. For the first time, a perianth is reported within basal florets of Schoenoplectus section Supini. Aerial florets of the same plants show no evidence of a perianth. In S. erectus ssp. raynalii and in S. lateriflorus ssp. lateriflorus, the perianth to the basal amphicarp consisted of two bristles with antrorse barbs. In S. articulatus, S. roylei and S. senegalensis the perianth comprised broader, smooth‐margined structures interpreted as scales. In some cases these were three per floret and were set at two levels suggestive of two whorls. Other amphicarpous species of the section showed basal florets without a perianth.