News Articles

Abstract

Key message

The deciduous species of the Aronia and Pourthiaea genera are differentiated by the finger-shaped colleters present on the midrib of the adaxial side and the pronounced cuticular folding.

Abstract

This work presents data on taxonomically significant features of leaf micromorphology in six deciduous species from the closely related genera Aronia and Pourthiaea of the subtribe Malinae (formerly Pyrinae, Maloideae) in the family Rosaceae. All species were found to have hypostomate leaves with numerous anomocytic stomata on the abaxial side. However, Aronia arbutifolia, Pourthiaea arguta, and P. villosa showed single stomata on leaf teeth on the adaxial leaf side. All species exhibited stomatal dimorphism, with a large single ‘primary’ stomata at the center of a cluster of smaller ‘secondary’ (ordinary) stomata. Aronia species were characterized by well-defined cuticular striations on the surface of the adaxial epidermis, as well as cuticular radial folds and peristomatic folds in both types of stomata. Cuticular folding in Pourthiaea species is restricted to radial folds in primary stomata and is less pronounced or absent in secondary stomata. All species of Aronia and Pourthiaea have colleters of deltoid or elongated shape in leaf teeth. In A. mitschurinii and A. arbutifolia, rounded colleters were found in the sinuses between the leaf teeth. Aronia species have the unique feature of forming a special type of colleters on the adaxial side of the leaf midribs. In contrast, Pourthiaea species lacked similar structures. The secretion of the colleters showed an intense peak at 670-674 nm with a small shoulder in the range of 695-740 nm in its fluorescence spectrum. The micromorphological features of the studied leaf structures can serve as taxonomic characters in the genera Aronia and Pourthiaea.

Abstract

Key message

Flexure wood formation is not systematically observed as a part of thigmomorphogenetic syndrome induced by wind. Its formation depends likely on the dose of mechanical signal perceived and the tree size-dependent strategy to resist wind loads.

Abstract

Formation of a specific wood tissue called flexure wood often accompanies the thigmomorphogenetic syndrome in mechanically stimulated trees. Flexure wood exhibits high microfibril angle allowing for increase in the stem flexibility and higher resistance to post-elastic damage during repeated loadings. In this study, we examine the microstructure and the properties of wood produced by beech poles submitted to increased mechanical stimulus. Contrary to previous results obtained on poplar saplings, aside a little decrease in density no changes in the microstructure or the post-elastic properties of wood were observed in beech poles. While in saplings wood properties explained 25% of the resistive moment increase and 50% of the maximal curvature decrease, their relative contribution was of 6% for the resistive moment and 5% for the maximal curvature decrease in beech poles. These apparent discrepancies between our results and previous studies were explained by a possible combination of three factors: (i) experienced level of mechanical stimulus, (ii) tree size-dependent shift in the strategy to resist wind loads and (iii) the species sensitivity to thigmomorphogenetic syndrome. We further suggest the use of juvenile transition as an indicator of the species strategy to cope with environmental signals adopting a broader view of the adaptive capacity of a given species.

Abstract

Key message

Our results from transcriptomics extend the understanding of the gene expression and major events associated with embryogenesis progression in Taxodium distichum × Taxodium mucronatum.

Abstract

Zygotic embryogenesis is a critical process during seed development in which the plant body plan is established and the meristems responsible for all post-embryonic growth are determined. Taxodium ‘Zhongshanshan’ is a series of superior interspecies hybrids of T. distichum and T. mucronatum and has been widely planted in southeastern China. Understanding the molecular, cellular and metabolic processes of embryonic development will provide important information on the somatic embryogenesis of T. ‘Zhongshanshan’ and further developing zygotic embryogenesis research. In the present study, we sequenced the transcriptomes of zygotic T. distichum × T. mucronatum embryos at several developmental stages, covering most of embryogenesis. Total RNA samples from six zygotic embryo developmental stages were collected for high-throughput RNA sequencing. In total, 46,798 unigenes were identified, and 12,846 differentially expressed genes were annotated. Genes involved in carbohydrate metabolic, such as glycoside hydrolase-, alpha-xylosidase- and xyloglucan endotransglycosylase-encoding genes, were over-represented in early embryogenesis. Genes associated with auxin, gibberellin, and cytokinin signaling pathways and epigenetic genes related to chromatin remodeling, DNA methylation, and histone deacetylase showed significant differential expression during the embryo development process. Moreover, a number of transcription factors related to embryonic development were identified, among which WUSCHEL HOMEOBOX (WOX), NO APCAL MERISTEM (NAM), and LEAFY COTYLEDON1 (LEC1) being more relevant during early and mid-embryogenesis stages. Our results will provide a valuable resource for future studies and will be helpful to the research of T. ‘Zhongshanshan’ breeding programs.

Abstract

Pisonia grandis R. Br. is a tree commonly found in urban coastal and tropical regions, valued for its ornamental beauty and utility in agroforestry and traditional medicine. To facilitate its propagation, particularly through in vitro techniques, this study aimed to refine a propagation system by inducing adventitious buds from node explants of mature tree. The study revealed that the Murashige and Skoog (MS) medium, supplemented with 30 g L⁻¹ sucrose and 2.0 mg L⁻¹ thidiazuron (TDZ), effectively stimulated bud break. Furthermore, a combination of 1.0 mg L⁻¹ TDZ and 0.5 mg L⁻¹ α-naphthalene acetic acid (NAA) yielded optimal shoot multiplication, resulting in an average of 16.0 shoots per explant with a length of 5.9 cm. In contrast, utilizing 1.0 mg L⁻¹ 6-benzylaminopurine (BAP) and 0.5 mg L⁻¹ NAA led to producing 10.0 shoots with a height of 3.7 cm. Incorporating TDZ significantly enhanced shoot numbers, size, and overall health of the shootlets. Microscopic analysis revealed that leaves and petioles derived from the TDZ and NAA combination exhibited desirable features, such as a thick cuticle, well-differentiated epidermis, mesophyll, vascular tissues, stomata, and improved vein density compared to those derived from BAP and NAA. The maximum root percentage (87.5%) and adventitious root formation (averaging 8.0 roots with a length of 6.2 cm) were observed on half-strength media supplemented with 1.5 mg L⁻¹ indole-3-butyric acid (IBA). Conversely, NAA fortification resulted in lower rooting percentages (77.8% response with an average of 4.7 roots measuring 4.0 cm in length). Subsequently, the rooted plantlets were successfully acclimatized using a mixture of soilrite®, cocopeat, and garden soil (1:1:1 v/v ratio), with a survival rate of 92.0% in the field. This study contributes valuable insights into the optimized use of growth regulators for the large-scale propagation of P. grandis and related species, ensuring the production of micro-morpho-structurally stable plantlets.

If your Monstera leaves aren’t splitting, there could be several ways to fix the problem. Here’s how to get that lovely Swiss cheese look.

Find the perfect holiday gifts for plant lovers! From stylish pots to unique houseplants, give presents that cultivate joy long after the season ends.

The current mainstream narrative is that climate change is caused by carbon dioxide (CO2) emissions from fossil fuels and methane emissions from farm animals. The solution is to reduce fossil use, scale up renewable energy, and eat less, preferably no, meat. Read here for more information.

The post Soil Organic Matter – the Most Critical Cause and Solution to Climate Change appeared first on Regeneration International.

Today we go back up to Vancouver, BC, and my quick visit earlier in the month. After we finished up at Claude’s garden, he took us over to visit Dan’s place. Pulling up out front I wasn’t sure what to expect as a tall hedge kept most of the garden hidden.

Even the entrance was veiled to protect it from prying eyes.

Damn, that’s a tall trachycarpus!

Oh! Love the deco-style home! (those tall cylindrical pots would have plants in them if my visit had been earlier in the year)

Turning now with my back to the house and looking out towards the hedge we saw earlier. I believe I heard that Dan made those custom stepping stones.

Taking the path that veers to the right…

And back to walk the other leg…

What fun pruning.

I was told in the summertime these pots hold agaves.

We’re in the back garden now where things are buttoned up for winter.

On the other side of the back wall there’s a veggie garden…

Dan made these raised beds out of pavers turned on their side and enclosed within a custom frame. Easy to take apart and move when the time comes. Genius!

A final look at the vegetable area…

… and we walk in towards the house, seeing the first of three (!!!) greenhouses…

And inside there’s a blooming lewisia!

Inside the big greenhouse, a blooming Huernia zebrina…

… and lemons!

I bet it’s a beautiful sight in here at night, as there’s a collection of colored glass lamps hanging from the ceiling. As a nod to practicality the hanging pots have metal saucers fastened to the bottom to contain drips.

The residents of the bump-out.

There’s a large agave hiding back there!

Gorgeous staghhorn (Platycerium grande?)…

With an interesting side-growth.

Maybe a Blechnum gibbum, which I guess is now going by the name Oceaniopteris gibba?

Another Pitcairnia alata (if I’m remembering correctly this one is a baby from Claude’s plant).

Oh my! Another spectacular platycerium of some sort I think?

The agaves are up on the top shelf where they can’t hurt anyone (smart since they also don’t need watering over the winter, but it must have been hell to get them up there).

Baby mangaves, Dan does sell plants at specialty sales.

Like many gardeners he just can’t help but make more plants.

Now we’ve gone into the house to see the final greenhouse (that first one I shared a photo of, off the back of the house), this one is full of cactus.

Check out the tall square pots, they’ve got inserts so you’re not carrying around a heavy pot made heavier with soil.

Back out in the front garden now, where there were ginger blooms (perhaps Hedychium densiflorum?) that I missed the first time through. Thanks for letting some crazy American with a camera tour your marvelous garden (and house) Dan! 

With the opening of The Leaf Connection on Aug. 24, try this fun family-friendly activity with your kids using leaves you might encounter in your neighborhood or hike.

The post Plants that Ring in the Holiday Season appeared first on Desert Botanical Garden.

Spread the joy of Desert Botanical Garden this season with exclusive gifts sold at the Garden Shop that will ignite the adventurous side from your loved ones of all ages.

The post Holiday Gifts Ideas from the Garden Shop appeared first on Desert Botanical Garden.