Content of Capsaicinoids and Physicochemical Characteristics of Manzano Hot Pepper Grown in Greenhouse

The hotness of the chili fruit (Capsicum spp.) is mainly due to the presence of capsaicinoids (capsaicin, nordihydrocapsaicin and dihydrocapsaicin). The aim of the present research was to evaluate the content of capsaicinoids and characteristics of physicochemical quality in fruits of manzano hot pepper grown in the greenhouse. The experimental design used was completely randomized with 3 and 4 replications. The parameters evaluated were total capsaicinoids, vitamin C, total carotenoids (TC), total soluble solids (TSS), titratable acidity, pH, firmness and color of the fruit. Among the hybrids with the highest content of total capsaicinoids and vitamin C, L4XL8 and L5XL7 (27 371 and 21 700 SHU, respectively) stand out as well as L2XL5 with 809.35 mg 100 g-1. On the other hand, L2XL3 stood out for its TC content (1 515.98 μg 100 g-1); L2XL7 and L4Xl7 stood out for the concentration of TSS, maintaining the acidity level without major changes. Additionally, L7XL8 was a material that was characterized to have fruits with greater firmness (2.31 N) and chromaticity of color (intense yellow) of 72.96. Among the evaluated hybrids, there are materials that presented fruits with physical and chemical characteristics of quality, which could be considered important from the commercial point of view or genetic improvement

Growth dynamics of morphological and reproductive traits of Physalis peruviana L. M1 plants obtained from seeds irradiated with gamma rays

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

Inbreeding and Genetic Erosion from a Finite Model of a Synthetic Formed with Single Crosses

When a seed produced by a single-cross (SC) maize hybrid is sown, the resulting grain yield is usually lower than that of the hybrid due to the inbreeding generated. However, if a seed from a mixture of s hybrids were sown instead, the synthetic variety thus formed (SynSC) would have a lower inbreeding coefficient (FSynSC) and a higher grain yield. The grain yield s, the finite number of representatives of each parent SC (m) and the inbreeding coefficient of the parent lines of the SCs (F) are related to the FSynSC. In addition, randomness and the finite size of m can cause the loss of genes and genotypes and increase the FSynSC. The objectives of this study were to derive formulas for (1) expressing FSynSC in terms of m, F, and s, and (2) calculating the probability of the occurrence of gene and genotype loss. It was found that for the probability of no genotype being missing from the progeny representing a parent to be at least 0.95, it is necessary that m ≥ 15. It was also found that a sample size of 7 is sufficient for FSynSC to stabilize, more visibly as F is larger, and for the probability of the occurrence of erosion to be practically zero

Manual pollination in two tomatillo (Physalis ixocarpa Brot. ex Horm.) varieties under greenhouse conditions

Manual pollination used in breeding programs is costly because it requires a large amount of labor, so it is necessary to optimize the process. The aim of this study was to determine the optimal time to carry out manual pollination efficiently in tomatillo. Closed flower buds with yellow coloration were covered and five manual pollination times (days one, two, three, four and five) and one non-pollinated control were evaluated in two families of the Diamante and Manzano varieties. A 5 x 2 x 2 factorial treatment design was used in a randomized complete block experimental design with four replicates. The experimental unit consisted of 10 floral buds. The number of fruits (NF), fruit weight (FW), total seed weight (TSW), total number of seeds (TNS) and weight of 100 seeds (W100S) were evaluated. The highest efficiency was obtained when manual pollination was carried out on the second and third days. The Diamante variety had a higher NF (7.8), TSW (2.315 mg) and TNS (1.415.8), while Manzano Tepetlixpa had higher FW (420.17 g) and W100S (191,538 mg). Family one of the Diamante variety was superior in TNS, but family two had larger seed size. In Manzano Tepetlixpa there were no differences between families. On the other hand, Diamante reached its highest seed production with pollination on day three, without statistically exceeding day two. Manzano had higher seed production when pollinated on day two, but did not statistically exceed day three. Therefore, it was determined that the optimal period of pollination in tomatillo is between two and three days after having covered the floral buds

INDUCTION OF VARIABILITY IN SEEDLING VIGOR, MORPHOLOGICAL CHARACTERS AND SELF-INCOMPATIBILITY OF M1 PLANTS OF THREE VARIETIES OF Physalis ixocarpa Brot. THROUGH 60Co GAMMA RAYS

Background. The husk tomato (Physalis ixocarpa 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. Objective. 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). Methodology. 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. Results. 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. Implications. 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). Conclusions. 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

Calidad fisiológica de semillas de Physalis ixocarpa en función de madurez a cosecha y condiciones de almacenamiento

The deterioration of the seed during storage reduces its germinative capacity and the establishment of seedlings in the field. In seed of Physalis ixocarpa Brot., The levels of the environmental factors that affect its germination longevity and its physiological performance during the storage, as a function of the state of development at harvest, are unknown. In this research, seed of the Chapingo variety harvested in three stages of development (45, 55 and 65 days after pollination) was evaluated in three storage periods (0, 4 and 8 months) combined with five environments that included two temperatures (23.8 and 5.3 ° C) and two levels of relative humidity (24 and 81%). It was found that the seed can maintain its initial germinative capacity (70%) for at least 8 months when stored at low relative humidity (24%) or cold (5 ° C), since the combination of high relative humidity (81%) and temperature of 23 ° C cause deterioration of the seed. The deterioration is manifested in germination reductions of 70 to 29%, viability of 81 to 46%, radicle emergence speed of 20.4 to 9.9 radicles per day, emergence velocity of the aerial part of 6.3 to 2.3 seedlings per day, respiration Of 16.1 to 6.6 nmol CO2 g 1 s-1 and in an increase in electrical conductivity of 32 to 97 μS cm -1 g -1. The seeds of 55 days of age have already reached physiological maturity, as they germinate the same and with the same vigor as the seeds of 65 days. The immature seeds of 45 days already have the capacity to germinate, although 10% less than the seed mature and with less vigor.El deterioro de la semilla durante el almacenamiento reduce su capacidad germinativa y el establecimiento de plántulas en campo. En semillas de Physalis ixocarpa Brot., se desconocen los niveles de los factores ambientales que afectan su longevidad germinativa y su desempeño fisiológico durante el almacenamiento, en función del estado de desarrollo a la cosecha. En esta investigación se evaluó semilla de la variedad Chapingo cosechada en tres estados de desarrollo (45, 55 y 65 días después de la polinización), en tres periodos de almacenamiento (0, 4 y 8 meses) combinados con cinco ambientes que incluyeron dos temperaturas (23.8 y 5.3 °C) y dos niveles de humedad relativa (24 y 81%). Se encontró que la semilla puede mantener su capacidad germinativa inicial (70%), por al menos durante 8 meses cuando se almacena en baja humedad relativa (24%) o en frío (5 °C), ya que la combinación de alta humedad relativa (81%) y temperatura de 23 °C causan el deterioro de la semilla. El deterioro se manifiesta en reducciones de germinación de 70 a 29%, viabilidad de 81 a 46%, velocidad de emergencia de radícula de 20.4 a 9.9 radículas por día, velocidad de emergencia de la parte aérea de 6.3 a 2.3 plántulas por día, respiración de 16.1 a 6.6 nmol CO2 g 1 s-1 y en un aumento en conductividad eléctrica de 32 a 97 µS cm-1 g-1. Las semillas de 55 días de edad ya han alcanzado la madurez fisiológica, pues germinan igual y con el mismo vigor que las semillas de 65 días. Las semillas inmaduras de 45 días ya poseen capacidad de germinar, aunque 10% menos que la semilla madura y con menor vigor