Seed germination response of Indian wild pear (Pyrus pashia) to gibberellic acid treatment and cold storage

Knowledge of seed germination behaviour of different seed sources of tree species is useful in selecting the most responsive and adaptive ones for propagation and germplasm conservation. The wild Himalayan pear (Pyrus pashia Buch-Ham ex D. Don) produces highly nutritious edible fruits that are consumed by local communities. The populations of the species are threatened due to exploitation and lack of adequate conservation programmes. The study was conducted to examine the germination response of P. pashia seeds from two sources (S1-Champawat and S2-Pithoragarh) in Uttarakhand state of India, to different GA3 treatment and also to assess the viability and longevity of the seeds in cold storage (5 °C) for three years. In both sources germination percent (GP) increased significantly under GA3 treatment and speed of germination was also enhanced (reduction in mean germination time). In Source, 1 GP increased under all GA3 application, highest being 94% under GA3 500 ppm treatment. In Source 2, GP of seeds doubled under 100 ppm GA3 treatment while its higher concentrations did not improve the germination. However, the differences observed in germination between the seed sources could be due to differences in the dormancy levels and/or sensitivity to dormancy breaking elements across their geographical range. Thus, exogenous application of GA3 is suggested for enhancing the germination in seeds of P. pashia. Seeds responded to cold storage by increased germination with duration, i.e. highest after three years in storage, indicating that the seeds got the required chilling treatment for overcoming dormancy.

The Influence of Flower Head Order and Gibberellic Acid Treatment on the Hydroxycinnamic Acid and Luteolin Derivatives Content in Globe Artichoke Cultivars

Flower head orders and the use of GA3 (gibberellic acid) treatment could be two influencing factors determining the bioactive compound levels in artichoke, but little to no information is available about their effects. In this study, we have therefore evaluated the influence of these factors on the hydroxycinnamic acid and luteolin derivative levels in three categories of artichoke: Seed-propagated open-pollinated cultivars; vegetatively propagated cultivars; and seed-propagated hybrids. The hydroxycinnamic acids and luteolin derivatives were quantified by RP-HPLC-DAD. The average flower head weight was the lowest in tertiary heads and GA3-treated artichokes, followed by secondary and main heads. Moreover, the hydroxycinnamic acid and luteolin derivatives levels were significantly higher in tertiary heads than in secondary or main heads. In addition, the GA3 treatment significantly reduced the hydroxycinnamic acid content and, in contrast, improved luteolin derivatives levels. These effects depended on the flower head order and cultivar. Knowledge of the effects of flower head order and GA3 treatment is therefore key in order to achieve the greatest health-benefits from artichoke consumption.

Seed germination of Allochrusa gypsophiloides(Caryophyllaceae), an endemic species from Central Asia and Kazakhstan

The results of evaluating the laboratory seed germination of endemic Allochrusa gypsophiloides (Turkestan soap root), depending on storage conditions in combination with gibberellic acid treatment (GA3), are presented. In dry storage, control seeds were characterised by a long after-ripening period and a fluctuating germination behaviour upon removal from storage, with a maximum value of 23%. The sensitivity of seeds to GA3 during dry storage varied significantly, with two germination peaks at 5-7 months, and 12 months (37.5 and 50% germination, respectively). Cold stratification and cryo-preservation accelerated seed after-ripening, promoted germination synchronisation and increased seed sensitivity to GA3. The cold stratification of seeds increased germination four months earlier than during dry storage. GA3 increased germination from 16.7 and 18.3% for the control to 37.5 and 45% for seeds cryopreserved for 5 and 12 months, respectively. We recommend cryopreserving Turkestan soap root seeds to avoid viability loss and to then germinate the seeds after pretreatment with GA3.

Effects of Seasonal Variation and Gibberellic Acid Treatment on the Growth and Development of Gypsophila paniculata

We investigated the effects of different planting seasons and gibberellic acid treatments on the growth and development of Gypsophila paniculata to explore new approaches to controlling the flowering period. Four different cultivars were selected and continually planted in July, September, and November in the low-latitude and high-altitude region of Kunming, China (25° N, 102° E). Results showed that the vegetative growth and flowering time of Gypsophila paniculata were prolonged and postponed when the planting time was delayed. Specifically, ‘My Pink’ showed 20% and 80% rosette rates when grown in autumn and winter, respectively, thus indicating that Gypsophila paniculata is sensitive to planting time. Moreover, GA3 treatment not only can significantly promote vegetative growth but also can stimulate early flowering and suppress the occurrence of rosettes during winter. This is more specific to ‘My Pink’, which showed 40% and 80% reductions in rosette rates with four and eight GA3 treatment applications, respectively. Our study showed that seasonal variations in the growth and development of Gypsophila paniculata and GA3 treatment can effectively stimulate early flowering and suppress rosettes during winter.

Flowering and nutritional status of Gladiolus hybridus L. ‘Black Velvet’ following gibberellin treatment

Flowering and nutritional status in Gladiolus hybridus L. ‘Black Velvet’ were assessed following gibberellic acid treatment (GA₃). Treatment were applied to corm (12–14 diameter) by soaking for 30 min in water solutions of GA₃ at 100, 350 and 600 mg/dm³with a control consisting of soaking-in water. All GA₃ treatments inhibited elongation of inflorescence shoots and stimulated spike elongation. None of the tested concentrations affected the number of developing flowers in the spike, except for the 100 mg/dm³ in the 2nd year of the study. All GA₃ treatments stimulated calcium uptake, but had no effect on the uptake of other macronutrients. All the GA₃ treatments increased manganese content in leavesbud did not affect copper content. GA₃ at 600 mg/dm³ stimulated uptake of iron and boron at 600 mg/dm³ but inhibited both at lower concentrations. Zinc uptake was stimulated at 100 mg/dm³but inhibited at higher concentration.

Effects of Pre-Treatment of Gibberellic Acid Solution on Musa sikkimensis Seeds

Musa sikkimensis Kurz (Musaceae) is one of the most popular banana species in the western world. It is near-hardy, surviving temperatures down to 0°C, but its propagation and cultivation are little researched. This study investigates the effects of gibberellic acid treatment on germination of Musa sikkimensis seeds. Enhanced germination rates will offer nurseries, botanic gardens and amenity growers the opportunity to increase their cultivation success. The findings are compared with those of other Musa species.