La inducción de mutaciones es una alternativa para generar variabilidad genética en la naturaleza, o para incrementar la variabilidad genética en una población y obtener genotipos que pueden emplearse como progenitores en programas de fitomejoramiento. La uchuva (Physalis peruviana L.) es una Solanacea cuyo fruto es una baya de sabor agridulce; cuyas semillas presentan germinación tardía. El objetivo del presente estudio fue evaluar el efecto de los rayos gamma 60Co sobre características de germinación de la semilla y vigor de plantas de P. peruviana. El estudio se realizó en invernadero con cubierta de plástico UVII720, de agosto a octubre de 2015. Los tratamientos fueron 16 dosis de rayos gamma 60Co (Gy): 0, 5, 10, 20, 50, 75, 100, 125, 150, 175, 200, 225, 250, 275, 300 y 350. El experimento se realizó en un diseño completamente al azar con cuatro repeticiones. La radiación no afectó el porcentaje de germinación, ni el número de hojas, pero las plántulas de semillas irradiadas emergieron 8 d antes que el testigo; con 300 y 350 Gy la supervivencia fue menor a 50 %. Las plantas de semillas irradiadas con 125, 150, 200 y 225 Gy presentaron la mayor altura y diámetro de tallo. La mayor lectura SPAD y longitud de la raíz se observaron en las plantas testigo. La mayor longitud de entrenudo se tuvo con 125, 150, 175 y 200 Gy. Mediante la aplicación de rayos gamma 60Co pueden modificarse las características de la velocidad de germinación y algunas variables relacionadas con el establecimiento y vigor de las plantas de uchuva.

There is an increasing interest in the development of uchuva (Physalis peruviana L.) cultivars adapted to greenhouse farming. Sexual behavior makes it difficult to obtain uniform commercial uchuva cultivars by conventional breeding methods. Mutations induced by gamma rays is an alternative approach. M1 plants derived from 14 irradiation 60Co doses, from 0 to 275 Gy, that were applied to uchuva seeds were evaluated. Recorded data included days to first flower and growth dynamics (four to seven samplings) of morphological traits (plant height, stem diameter, basal stems) and reproductive traits (floral buds, flowers and green fruits). Treatments were distributed in a completely randomized blocks experimental design with six replications, in a greenhouse. The experimental unit was a single M1 plant. Statistical differences were found for irradiation doses, growth samplings, and its interaction. Growth dynamics results indicate that all traits showed a linear increase with plant age (R2 = 0.92* to 0.98**), but the effect of the irradiation doses on morphological and reproductive traits was no linear. Irradiation reduced plant height by 79%. M1 plants developed from irradiated seeds at doses of 125, 175 and 200 Gy showed greater stem diameter, with more basal stems, floral buds, flowers and green fruits than the control. It is concluded that intermediate irradiation doses had a stimulating effect on vegetative growth and fruiting traits of M1 uchuva plants.

<p><strong>Background.</strong> The sweet biznaga (<em>Echinocactus platyacanthus</em>) is endemic to Mexico, whose seeds show low germination, viability, longevity, genetics, and latency; therefore, gamma irradiation is an alternative to stimulate the emergence and growth of seedlings, by causing variations in the chemical composition of DNA, which causes cytological, biochemical, physiological and morphological changes in plants. <strong>Objective.</strong> The objective of the present investigation was to evaluate the effect of different doses of gamma ⁶⁰Co radiation on seed germination and seedling vigor of <em>E. platyacanthus</em>. <strong>Methodology.</strong> <em>E. platyacanthus</em> seeds were irradiated at 0, 50, 100, 150, 200, 250, 300, 350, 400, 450, 500 and 550 Gy of ⁶⁰Co gamma rays, then they were sown in transparent plastic containers covered with filter paper and were distributed in a completely randomized design with four repetitions in a germination chamber, the percentage of germination and survival of seedlings in the container was recorded 30 days after sowing (das). The seedlings were transplanted at 30 das into black polyethylene bags with tezontle and established in a completely randomized design with 12 treatments and four replications, in a tunnel-type greenhouse. At 20 and 30 days after transplantation (dat) seedling vigor was measured based on height (cm), stem diameter (mm) and root length (mm) and at 20 dat survival was recorded (%) of seedling in the substrate. An analysis of variance and Tukey's test for comparison of means (p ≤ 0.05) were performed. <strong>Results.</strong> Gamma irradiation stimulated seed germination from 10 to 29%. In seedlings, root height and length were modified with intermediate doses of gamma rays (100 to 200 Gy); but higher doses negatively affected these indicators. Survival of containerized M₁ seedlings was up to 63% higher than the control, depending on the irradiation dose. <strong>Implications.</strong> Irradiation with ⁶⁰Co gamma rays improves seed germination, survival and vigor of <em>E. platyacanthus</em> seedlings. <strong>Conclusions.</strong> Irradiation with ⁶⁰Co gamma rays stimulated seed germination and improved some characteristics of vigor in <em>E. platyacanthus</em> seedlings, by modifying root height and length according to age. In addition, it increased the survival of containerized seedlings.</p>

<p><strong>Background. </strong>The husk tomato (<em>Physalis ixocarpa</em> Brot. ex Horm.) is an obligated allogam species with gametophyte auto-incompatibility, which impedes the generation of endogamic lines by auto-fecundation to obtain hybrids. <strong>Objective.</strong> To evaluate the effect of six doses of ⁶⁰Co gamma rays (from 0 to 300 Gy) applied to seeds, over seedling vigor, growth and reproductive features of M₁ plants of three husk tomato varieties (Manzano, Verde Puebla, and San Miguel). <strong>Methodology.</strong> The 18 treatments were distributed in a completely randomized design with five replications for the variables related to seedling vigor and 10 replications for the morphological and reproductive plant variables. <strong>Results.</strong> The radiation decreased emergency and survival of seedlings, height, and length of roots of M₁ seedling. Regarding the growth of M₁ plants, the doses of 100 and 300 Gy stimulated only height, the other doses had the same response as the control. Irradiation did not change self-incompatibility, as no fruit produced seed. <strong>Implications.</strong> The study allows to determine the sensitivity of the peel tomato to irradiation, by subjecting seeds to different doses of gamma rays and assess whether it is possible to obtain outstanding individuals in force and flowers that present self-fertilization, considering all the advantages of this type of pollination (form lines, to generate hybrids). <strong>Conclusions.</strong> The M₁ plants of the varieties Manzano and Verde Puebla excelled in growth; but those of San Miguel presented more self-pollinated flowers. The three varieties resulted sensitive to radiation; but growth variables varied depending on the variety and dose of radiation.<strong></strong></p>

Objective: To measure the phenology, morphology and development of four varieties ofPhysalis peruviana L. under greenhouse and hydroponics conditions, by effect of the ionicstrength of the Steiner nutrient solution for cultivation in Mexico.Design/Methodology/Approach: The research was conducted under a completelyrandom design with factorial arrangement, the treatments evaluated resulted from thecombination of the levels of the variety factor (Colombia, Sacha, Chiclayo and Modified)with the levels of the ionic strength of the Steiner nutrient solution (50, 100 and 150%),and the experimental unit was a potted plant. For phenology each phase was recorded inthe plants, SPAD readings were taken in the vegetative stage, for diameter and heightseveral samples were taken, and pH and electrical conductivity were accomplished onstems and petioles of shoots of each treatment. An analysis of variance and thecomparison of means per Tukey (p ? 0.05) were implemented with the SAS 9.2 program.Results: The varieties under study showed differences in the time of occurrence of thephenological stages. SPAD readings, basal diameter, pH and electrical conductivity in sapwere affected by each factor except for the interaction. Meanwhile, plant height wassignificantly affected in the first 24 days after transplant (dat) by the combination of thetwo factors. Study Limitations/Implications: The results obtained are limited to the varieties, theenvironmental conditions, and the time when the varieties were evaluated.Conclusions: The phenology of each variety was not expressed at the same time in anyconcentration, as an early variety was given to Chiclayo, Colombia and Sacha, which arevarieties that in the concentrations 50 and 150% of the nutrient solution started harvestingat 99 dat.