Seed viability of five wild Saudi Arabian species by germination and X-ray tests

Ex-situ conservation of wheat genetic resources from Saudi Arabia

Wheat (Triticum L.) is one of the major food crops of the world, and an important component of food security. The aim of this study was to collect and preserve seeds of wheat growing in eight regions of the Kingdom of Saudi Arabia (Al-Qassim, Asir, Al-Taif, Najran, AL-Baha, Jazan, Al-Madinah and Wadi Al-Dawasir) where wheat has been cultivated since ancient times. Sixty-one accessions/samples of wheat (Triticum aestivum) were collected and placed in dry storage (ex-situ conservation) at −18 °C (i.e. permanent storage). The accessions of local wheat have the ability to grow under harsh environmental conditions such as (high temperature, drought and salinity). Most of these samples were collected directly from farms, but a few were collected from markets. The most important criteria for ex-situ conservation is that seeds need to have a low moisture content (MC) and a high percentage viability. Seed MC was measured for all 61 accessions by the oven-drying method and seed viability was tested in three ways: percentage of germination, tetrazolium chloride testing, and X-ray radiography.

The seed MC of the 61 accessions was uniformly very low (0.10–0.12%), and 97 to 100% of the seeds were viable. Thus, all 61 wheat accessions collected in this study have the initial requirements to remain viable for long periods of time in ex-situ conservation in the gene seed bank.

Optimización de la prueba de tetrazolio para evaluar la viabilidad en semillas de Solanum lycopersicum L

El tomate (Solanum lycopersicum) es una de las hortalizas más consumidas en el mundo con un aumento en su demanda, por lo que conocer la viabilidad de sus semillas es de suma importancia, ya que estas son la base del éxito de su producción. Debido a esto, el presente estudio tuvo como objetivo optimizar la prueba de tetrazolio determinando el pretratamiento adecuado para potenciar la prueba. El material vegetal se recolectó de cultivos establecidos en el municipio del Cáchira, departamento de Norte de Santander, Colombia. Las semillas se extrajeron de los frutos maduros y, posteriormente, se expusieron a pretratramientos con hipoclorito de sodio y agua destilada durante 10 minutos, con tres concentraciones de 2, 3, 5- cloruro trifenil tetrazolio (0,25 %, 0,15 % y 0,10 %) y distintos tiempos de exposición (6 h, 12 h y 24 h). Los datos de viabilidad obtenidos se corroboraron mediante la prueba de germinación en toallas de papel húmedas. Los resultados de viabilidad más relacionados con la prueba de germinación se obtuvieron al emplear las concentraciones de 0,25 % y 0,15 %, utilizando tanto el pretratamiento con hipoclorito de sodio como la inmersión en agua destilada.  

Rapid and Nondestructive Measurement of Rice Seed Vitality of Different Years Using Near-Infrared Hyperspectral Imaging

Seed vitality is one of the primary determinants of high yield that directly affects the performance of seedling emergence and plant growth. However, seed vitality may be lost during storage because of unfavorable conditions, such as high moisture content and temperatures. It is therefore vital for seed companies as well as farmers to test and determine seed vitality to avoid losses of any kind before sowing. In this study, near-infrared hyperspectral imaging (NIR-HSI) combined with multiple data preprocessing methods and classification models was applied to identify the vitality of rice seeds. A total of 2400 seeds of three different years: 2015, 2016 and 2017, were evaluated. The experimental results show that the NIR-HSI technique has great potential for identifying vitality and vigor of rice seeds. When detecting the seed vitality of the three different years, the extreme learning machine model with Savitzky-Golay preprocessing could achieve a high classification accuracy of 93.67% by spectral data from only eight wavebands (992, 1012, 1119, 1167, 1305, 1402, 1629 and 1649 nm), which could be developed for a fast and cost-effective seed-sorting system for industrial online application. When identifying non-viable seeds from viable seeds of different years, the least squares support vector machine model coupled with raw data and selected wavelengths of 968, 988, 1204, 1301, 1409, 1463, 1629, 1646 and 1659 nm achieved better classification performance (94.38% accuracy), and could be adopted as an optimal combination to identify non-viable seeds from viable seeds.

Conservation of genetic resources for five traditional crops from Jazan, SW Saudi Arabia, at the KACST Gene-Bank

The conservation of five traditional crops is an important aspect of achieving national food security. In the present study, we aimed to collect and conserve germplasm of five local crops from the Jazan region of southwestern Saudi Arabia: Sorghum: Sorghum bicolor (L.) Moench); Barley (Hordeum vulgare L.) Millet (Pennisetum glaucum (L.) R. Br.); Sesame (Sesamum indicum L.) and Guar (Cyamopsis tetragonoloba (L.) Taub). Forty-one seed accessions of these five crops were collected and tested to determine seed moisture content (MC%) and quality as indicators of their potential to survive during long-term dry storage at −18 °C (i.e. ex-situ conservation of genetic resources). Seed viability was assessed using germination tests, the tetrazolium chloride (TZ) test and X-ray imaging. Seeds of the five crops had very low MC% and high viability (fully developed embryos and germination >91%), indicating that they were of good quality and had high potential for long-term survival in gene banks. The genetic resources of these crops (seeds) have now been preserved at the gene-bank of King Abdulaziz City for Science and Technology (KACST-BGB), Riyadh, Saudi Arabia.