Relationship between Key Environmental Factors and the Architecture of Fruit Shape and Size in Near-Isogenic Lines of Cucumber (Cucumis sativus L.)

Evaluation of morphological traits, biochemical parameters and seeding availability pattern among Citrus limon 'Assam lemon' accessions across Assam

The Assam lemon is a highly valued Citrus cultivar known for its unique aroma, flavor, and appearance. This study aimed to investigate the morphological, seeding pattern and biochemical variations within 132 populations of Assam lemon from across 22 districts of Assam along with the control samples, with the objective to offer comprehensive understanding that could facilitate the improvement of breeding programs and further improvement of this important cultivar. Clustering based on UPGMA algorithm for morphological and seeding pattern data were analysed at population level, revealed two major clusters, where all the populations of Upper Assam districts were in the same cluster with the original stock (control population). The populations from Tinsukia and Dhemaji districts displayed more close similarities with the control population in comparison to populations of Upper Assam districts. Another interesting observation was regarding flowering patterns, while populations from Upper Assam districts excluding Golaghat district displayed both bisexual and unisexual flowers with less concentration of unisexual flowers, other remaining districts had bisexual and unisexual flowers of almost equal concentration. Unisexual flowers contained only the male reproductive organs with 40 anthers, while bisexual flowers had 36 anthers. Seeding patterns were examined across the districts, and it was found that populations from Tinsukia, Dhemaji, Lakhimpur, Dibrugarh, Jorhat, and the control population exhibited seedless characteristic while populations from other selected districts displayed a combination of seedless and seeded traits. Interestingly, Golaghat district appears as the linking district and showed availability of both seeded and seedless Assam lemon fruit, connecting the regions of Barak valley, Central, Lower, North and Upper Assam. Biochemical analysis showed significant variations across districts, however, the populations from Dhemaji, Tinsukia, Lakhimpur, Dibrugarh, and Jorhat districts displayed similarity with the control population. The study also investigated variability in soil nutrient content revealing substantial variation among the populations studied. This comprehensive investigation provides valuable insights into the morphological, seeding pattern, and biochemical diversity within the Assam lemon cultivar. These findings can be instrumental in breeding programs to enhance the cultivar, particularly in producing high-quality seedless fruits to meet consumer demands.

Patterns of Leaf and Fruit Morphological Variation in Marginal Populations of Acer tataricum L. subsp. tataricum

Marginal populations are usually smaller and more isolated and grow in less favourable conditions than those at the distribution centre. The variability of these populations is of high importance, as it can support the adaptations needed for the conditions that they grow in. In this research, the morphological variability of eight Tatar maple (Acer tataricum L. subsp. tataricum) populations was analysed. Tatar maple is an insect-pollinated and wind-dispersed shrub/tree, whose northwestern distribution edge is in southeastern Europe. Morphometric methods were used to analyse the variability of the populations using leaf and fruit morphology. The research revealed significant differences between and within populations. Furthermore, differences in the distribution of the total variability were noted, which suggest that different evolutionarily factors affect different plant traits. Correlation analysis confirmed a weak dependency between the vegetative and generative traits. In addition, no evidence was found for the presence of isolation by environment (IBE). However, the Mantel test for isolation by distance (IBD) was significant for the leaf morphometric traits and non-significant for the fruit morphometric traits. Being the marginal leading-edge populations, they are younger and were less likely to have had time for adaptation to local environments, which would have resulted in the development of IBE. Overall, edge populations of Tatar maple were characterised by great morphological variability, which helps these populations in their response to the intensive selective pressures they face in their environment.

Environmental Stress and Plants 2.0

Following the success of our previous edition [...].

Genome-Wide Identification of the SUN Gene Family in Melon (Cucumis melo) and Functional Characterization of Two CmSUN Genes in Regulating Fruit Shape Variation

Melon (Cucumis melo) is an important economic crop cultivated worldwide. A unique SUN gene family plays a crucial role in regulating plant growth and fruit development, but many SUN family genes and their function have not been well-characterized in melon. In the present study, we performed genome-wide identification and bioinformatics analysis and identified 24 CmSUN family genes that contain integrated and conserved IQ67 domain in the melon genome. Transcriptome data analysis and qRT-PCR results showed that most CmSUNs are specifically enriched in melon reproductive organs, such as young flowers and ovaries. Through genetic transformation in melons, we found that overexpression of CmSUN23-24 and CmSUN25-26-27c led to an increased fruit shape index, suggesting that they act as essential regulators in melon fruit shape variation. Subcellular localization revealed that the CmSUN23-24 protein is located in the cytoplasmic membrane. A direct interaction between CmSUN23-24 and a Calmodulin protein CmCaM5 was found by yeast two-hybrid assay, which indicated their participation in the calcium signal transduction pathway in regulating plant growth. These findings revealed the molecular characteristics, expression profile, and functional pattern of the CmSUN genes, and may provide the theoretical basis for the genetic improvement of melon fruit breeding.