International Journal of Plant Biology

Systems favoring cross-pollination, such as male sterility and female flowering type, are of great importance in the development of new hybrid cultivars and their seed production. The advantages of male sterility are expressed in the production of cheaper and competitive seeds. The presence of this characteristic in watermelon is not common, and in some cases, it is accompanied by negative manifestations. A collection of 150 watermelon genotypes was tested at the Maritsa Vegetable Crops Research Institute, Bulgaria, over the past nine years to search for a genetic source of male sterility. The results revealed that two mutations were found. The first mutation was in a plant of the Asar variety, which formed completely degenerated structures in the place of male and female flowers that were completely sterile. The other mutation affected male flowers, female flowers, and leaf shape. Male flowers produced a small amount of pollen. Female flowers were formed, but they were sterile and aborted at an early stage. The genotype can be propagated by pollination of the normal plants, which in the next generation segregate into mutant—25% and normal—75%. The gene source is phenotyped according to the main characteristics of the fruits and the vegetation period. The mutation found cannot be directly used in a breeding program, but it is of interest for studying this important trait. The success of detecting flowers that are sterile depends on the number of watermelon plants, which, for the conditions of the experiment, amounted to a minimum of 4492 plants at a probability level of P₃—0.95.

Purple corn (Zea mays L.) is a nutraceutical crop of increasing economic importance in Peru, yet its productivity is highly influenced by genotype × environment (G × E) interactions across heterogeneous agro-ecological zones. Therefore, selecting suitable genotypes for specific environments is essential to optimize variety deployment and maximize site-specific yield. Five purple-maize genotypes (INIA-601, INIA-615, Canteño, PMV-581, and Sintético-MM) were evaluated in four contrasting Peruvian sites using a randomized complete-block design. Grain yield, field weight, anthesis–silking interval (ASI), plant height, and ear-rot incidence were analyzed with combined analysis of variance (ANOVA), the additive main effects and multiplicative interaction (AMMI), genotype and genotype-by-environment (GGE) biplots, Weighted Average of Absolute Scores (WAAS), weighted average of absolute scores and best yield index (WAASBY), and Y × WAAS indices. Environment accounted for 90.1% of field-weight variation (p < 0.0001) and 50.2% of grain-yield variation (p < 0.001), while significant G × E interactions (3.93% and 18.14%, respectively) justified bilinear modeling. AMMI1 and GGE “which-won-where” biplots identified INIA-615 and PMV-581 as broadly adapted, with INIA-615 achieving the highest WAASBY and positioning in quadrant IV of Y × WAAS (high yield, high stability). INIA-601 and Sintético-MM exhibited exceptional stability (low ASV) but moderate productivity; Canteño showed limited adaptability. Chumbibamba emerged as a key discriminating, high-productivity location. From an agronomic perspective, INIA-615 is recommended for high-productivity valleys such as Sulluscocha and Santa Rita, where its yield potential and stability are maximized. These findings underscore the potential of integrating multivariate stability metrics with physiological and disease-resistance traits to guide the selection of superior purple corn cultivars. Overall, INIA-615 represents a robust candidate for enhancing yield stability, supporting sustainable intensification, and expanding the nutraceutical value chain of purple corn in the Andean highlands.

The increasing environmental challenges facing modern agriculture necessitate development of sustainable, eco-friendly alternatives to chemical inputs. This study aimed to isolate and characterize rhizophilic bacterial strains from the rhizosphere of the maize hybrid Turan 480 SV (Zea mays L.), with a focus on their plant growth-promoting and biocontrol traits. A total of 23 bacterial isolates were obtained, including 15 Gram-negative and 8 Gram-positive strains. Among these, three strains—CR14, CR18 and CR22—were selected for detailed analysis. All three demonstrated significant indole-3-acetic acid (IAA) production, phosphate and zinc solubilization, nitrogen fixation and antifungal activity. CR14 synthesized 56.01 mg L⁻¹ of IAA and demonstrated the highest zinc solubilization, while CR18 exhibited superior phosphate solubilization and protease activity. CR22 produced the highest IAA (61.46 mg L⁻¹) and demonstrated strong cellulase and amylase activity. In antagonism tests, CR14 suppressed Alternaria alternata with an 80 mm inhibition zone, while CR18 and CR22 effectively inhibited both A. alternata and Fusarium graminearum. Phylogenetic analysis based on 16S rRNA sequencing identified CR18 as Serratia quinivorans, CR14 as Pantoea agglomerans and CR22 as Pantoea sp. The functional diversity of rhizobacteria holds promise as bioinoculants for enhancing maize growth and protecting against soil-borne pathogens in sustainable agriculture.