Effects of light spectra on growth and defence in potted Actinidia chinensis var. deliciosa ‘Hayward’ kiwifruit plants

Consumer acceptance of fruit is determined by size, flavour and ripeness. In this study we investigated how altering the carbohydrate supply to Actinidia chinensis var. chinensis ‘Zesy002′ kiwifruit altered the balance between growth and accumulation of metabolites. Canes were phloem girdled and fruit thinned to a leaf-to-fruit ratio (L:F) of either 2 (Low carbohydrate) or 6 (High carbohydrate) at either 38 (Early) or 86 (Late) days after anthesis (DAA) and compared with ungirdled control canes with a L:F of 3. Fruit growth, metabolite accumulation, cytokinin concentrations and maturation were monitored and the sensory attributes of ripe fruit were assessed. The final weight of Early-High and Late-High carbohydrate fruit was 38% and 16% greater compared with control fruit. High carbohydrate fruit had increased starch,soluble sugar and cytokinin concentrations and fruit began to mature earlier and those with a Low carbohydrate had decreased concentrations and matured later compared with control fruit. Control fruit were described by consumers as more acidic and under-ripe compared with those from Early-High carbohydrate canes, but as sweeter than those from Low carbohydrate canes. This study showed that carbohydrate supply can have a major impact on the growth, sugar accumulation and maturity of ‘Zesy002′ fruit sinks.

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Cytotype distribution and chloroplast phylogeography of the Actinidia chinensis complex

BMC Plant Biology ◽

10.1186/s12870-021-03099-y ◽

2021 ◽

Vol 21 (1) ◽

Author(s):

Zhi Wang ◽

Caihong Zhong ◽

Dawei Li ◽

Chunlin Yan ◽

Xiaohong Yao ◽

...

Keyword(s):

Environmental Changes ◽

Demographic History ◽

Wide Distribution ◽

Historical Demography ◽

Actinidia Chinensis ◽

Ecological Niche Models ◽

Subtropical China ◽

Modeling Tools ◽

Climatic Fluctuations ◽

Ploidy Levels

Abstract Background Plant phylogeographic studies of species in subtropical China have mainly focused on rare and endangered species, whereas few studies have been conducted on taxa with relatively wide distribution, especially polyploid species. We investigated the cytotype and haplotype distribution pattern of the Actinidia chinensis complex, a widespread geographically woody liana with variable ploidy in subtropical China comprising two varieties, with three chloroplast fragments DNA (ndhF-rpl132, rps16-trnQ and trnE-trnT). Macroevolutionary, microevolutionary and niche modeling tools were also combined to disentangle the origin and the demographic history of the species or cytotypes. Results The ploidy levels of 3338 individuals from 128 populations sampled throughout the species distribution range were estimated with flow cytometry. The widespread cytotypes were diploids followed by tetraploids and hexaploids, whereas triploids and octoploids occurred in a few populations. Thirty-one chloroplast haplotypes were detected. The genetic diversity and genetic structure were found to be high between varieties (or ploidy races) chinensis and deliciosa. Our results revealed that these two varieties inhabit significantly different climatic niche spaces. Ecological niche models (ENMs) indicate that all varieties’ ranges contracted during the Last Inter Glacial (LIG), and expanded eastward or northward during the Last Glacial Maximum (LGM). Conclusions Pliocene and Plio-Pleistocene climatic fluctuations and vicariance appear to have played key roles in shaping current population structure and historical demography in the A. chinensis complex. The polyploidization process also appears to have played an important role in the historical demography of the complex through improving their adaptability to environmental changes.

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Effect of various light spectra on amino acids and pigment production of Arthrospira platensis using flat-plate photobioreactor

Preparative Biochemistry & Biotechnology ◽

10.1080/10826068.2021.1941102 ◽

2021 ◽

pp. 1-12

Author(s):

Hanieh Tayebati ◽

Farshid Pajoum Shariati ◽

Neda Soltani ◽

Hessam Sepasi Tehrani

Keyword(s):

Amino Acids ◽

Flat Plate ◽

Arthrospira Platensis ◽

Pigment Production ◽

Light Spectra ◽

Flat Plate Photobioreactor

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Influence of Light Conditions and Medium Composition on Morphophysiological Characteristics of Stevia rebaudiana Bertoni In Vitro and In Vivo

Horticulturae ◽

10.3390/horticulturae7070195 ◽

2021 ◽

Vol 7 (7) ◽

pp. 195

Author(s):

Alla A. Shulgina ◽

Elena A. Kalashnikova ◽

Ivan G. Tarakanov ◽

Rima N. Kirakosyan ◽

Mikhail Yu. Cherednichenko ◽

...

Keyword(s):

Culture Media ◽

Stevia Rebaudiana ◽

Adventitious Shoot ◽

Optimal Growth ◽

Medium Composition ◽

Light Spectra ◽

Stevia Rebaudiana Bertoni ◽

Multiplication Coefficient

We investigated the influence of different conditions (light composition and plant growth regulators (PGRs) in culture media) on the morphophysiological parameters of Stevia rebaudiana Bertoni in vitro and in vivo. Both PGRs and the light spectra applied were found to significantly affect plant morphogenesis. During the micropropagation stage of S. rebaudiana, optimal growth, with a multiplication coefficient of 15, was obtained in an MS culture medium containing 2,4-epibrassinolide (Epin) and indole-3-acetic acid (IAA) at concentrations of 0.1 and 0.5 mg L−1, respectively. During the rooting stage, we found that the addition of 0.5 mg L−1 hydroxycinnamic acid (Zircon) to the MS medium led to an optimal root formation frequency of 85% and resulted in the formation of strong plants with well-developed leaf blades. Cultivation on media containing 0.1 mg L−1 Epin and 0.5 mg L−1 IAA and receiving coherent light irradiation on a weekly basis resulted in a 100% increase in the multiplication coefficient, better adventitious shoot growth, and a 33% increase in the number of leaves. S. rebaudiana microshoots, cultured on MS media containing 1.0 mg L−1 6-benzylaminopurine (BAP) and 0.5 mg L−1 IAA with red monochrome light treatments, increased the multiplication coefficient by 30% compared with controls (white light, media without PGRs).

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