Morphometric, weight, viability, and germination analysis of castor bean seeds (Ricinus communis) under two temperature and relative humidity conditions

Objective: Morphometric evaluation, weight, viability and germination under two conditions of temperature and relative humidity in sixteen local varieties of castor beans (Ricinus communis) from various states of Mexico (E1-E16) including two commercial varieties (k75B and k93B) were analyzed. Design/methodology/approach: The morphometric characteristics were: area, Elongation Index (IE) and Feret's diameter (DF), by means of a vision system. The viability and germination tolerance (germination percentage (% germination), germination speed (VG) and emergence speed index (IVE)), were evaluated under two conditions of relative humidity and temperature (T1- HR 80%/T20ºC ; T2- HR 30%/T40ºC), under a randomized complete block experiment design with four replicates of 75 seeds. Results: There are morphometric differences (IE, area and DF) between and within the study varieties. There is a significant difference between T1 and T2 in days of radicle emergence (11.6 in T2 and 44.71 in T1), germination percentage (T1: 48.37 and T2: 56%), IVE (T1:34.07+12.72 and T2: 77.02+ 23.78) and VG (T1: 9.93 and T2: 24.60). The results obtained show that there is a positive correlation between the morphometric properties and the germination percentage under T1; but in T2 no correlation was observed. The Limitations on study/implications: The study did not imply limitations. Findings/conclusions: Two local varieties E4 and E15 with productive potential higher than 93% under T1 were found; and under T2 the local varieties E3 and E16 with a productive potential greater than 78%, with respect to the commercial variety k75B showed a better performance under T1 (89.75%) than under T2 (78.67%).Objective: To analyze the morphometric, weight, viability, and germination evaluation under two temperature and relative humidity conditions, in sixteen local varieties of castor bean (Ricinus communis) from several states of Mexico (E1-E16), as well as two commercial varieties (k75B and k93B). Design/Methodology/Approach: The following morphometric characteristics were analyzed using a vision system: area, elongation index (EI), and Feret's diameter (FD). Viability and germination tolerance (germination percentage (GP)), germination speed (GS), and emergence speed index (ESI)) were evaluated under two conditions of relative humidity and temperature (T1 - RH 80%/T 20ºC; T2 - RH 30%/T 40ºC), using a completely randomized block experiment design, with four replicates of 75 seeds. Results: There are morphometric differences (EI, area, and FD) between and within the study varieties. There are significant differences between T1 and T2 regarding the following variables: days of radicle emergence (T1: 44.71 and T2:11.6), germination percentage (T1: 48.37 and T2: 56%), ESI (T1: 34.07+12.72 and T2: 77.02+ 23.78), and GS (T1: 9.93 and T2: 24.60). The results obtained show a positive correlation between the morphometric properties and the germination percentage in T1; however, there was no correlation in T2. Study Limitations/Implications: There were no limitations to carry out this study. Findings/Conclusions: The E4 and E15 local varieties obtained a >93% productive potential in T1, while the E3 and E16 local varieties obtained a >78% productive potential in T2. Meanwhile, the k75B commercial variety had a better performance in T1 (89.75%) than in T2 (78.67%)

The sperm factor: paternal impact beyond genes

The fact that sperm carry more than the paternal DNA has only been discovered just over a decade ago. With this discovery, the idea that the paternal condition may have direct implications for the fitness of the offspring had to be revisited. While this idea is still highly debated, empirical evidence for paternal effects is accumulating. Male condition not only affects male fertility but also offspring early development and performance later in life. Several factors have been identified as possible carriers of non-genetic information, but we still know little about their origin and function and even less about their causation. I consider four possible non-mutually exclusive adaptive and non-adaptive explanations for the existence of paternal effects in an evolutionary context. In addition, I provide a brief overview of the main non-genetic components found in sperm including DNA methylation, chromatin modifications, RNAs and proteins. I discuss their putative functions and present currently available examples for their role in transferring non-genetic information from the father to the offspring. Finally, I identify some of the most important open questions and present possible future research avenues