Abdullah A. Jaradat

Flowering, capsule and seed characteristics in Cuphea

We modeled the flowering and capsule set dynamics, quantified the level of variation in seed characteristics, elucidated the inter-relationships between seed and capsule physical dimensions, and quantified their impact on single seed weight in the cuphea germplasm line PSR23. Temporal patterns of flowering and capsule set were largely time-dependent and highly auto-correlated, with significant autoregressive parameters of number of flowers (0.76) and number of capsules (0.74). Large numbers of seeds per capsule were associated with large coefficient of variation in single seed weight. Seed number and seed weight per capsule, when log-transformed, exhibited a slope of −0.65 indicating that cuphea plants have only a limited capacity to maintain seed weight by adjusting seed number if resources vary. Capsule tissue/seed weight ratio and number of seeds per capsule have the largest potential impact on single seed weight. Sensitivity analyses indicated that capsule perimeter (>76xa0mm), capsule major (>23xa0mm) and minor axes (>7.0xa0mm), capsule circularity (between 0.350xa0and 0.375), capsule area (<85xa0mm2), capsule tissue/seed weight ratio (<0.40), and number of seeds per capsule (∼9.0) would optimize single seed weight. This information would help plant breeders exploit genotypic variability in seed and capsule characteristics and agronomists identify optimum trait combinations to produce high yields of this potential oilseed crop.

Use of Marginal Water for Salicornia bigelovii Torr. Planting in the United Arab Emirates

Freshwater resources are not enough to meet the ever increasing demand of the agriculture sector to feed the growing population. Owing to this reason, agriculture scientists are exploring different ways to use saline water as an alternative source for crops. Samphire (Salicornia bigelovii Torr.) is one of the best candidates for such plants that can be grown using seawater. It has high culinary value and can be consumed either cooked or raw. The plant can also be used as feed for different domestic animals. Since its seed contains high-quality unsaturated oil (30%) and proteins (40%), it can be used to make biodiesel and as animal feed. At the Dubai-based International Center for Biosaline Agriculture (ICBA), a field experiment was conducted using five different lines of Salicornia bigelovii irrigated with seawater. In general, all of the Salicornia lines grew well and gave good results. To evaluate their performance, data were recorded on 50 individual plants from each line at maturity. Data on 12 different morphological characteristics of spikes and plants were collected. The range for plant height varies from 49.2 to 63.0 cm. Minimum of 65.8 g and maximum of 91.8 g plant dry weight were recorded. The lowest seed weight per plant was 6.39 g, and the highest was 9.17 g. The results indicate that highly valuable Salicornia can be grown successfully in arid regions using seawater for irrigation.

Determinants and Prediction of Carbon/Nitrogen Ratio in Five Diverse Crop Plants

Multivariate relationships in and statistical moments of eight biochemical constituents and their impact on estimating carbon/nitrogen (C/N) ratio in alfalfa, corn, soybean, cuphea, and switchgrass residues indicate that (1) equal portions of variation in C/N were explained by differences among crops and among organs; however, the largest variations in N and C were explained by differences among crops and among organs within crops, respectively; (2) variation in N, but not in C or N + C, content explained the greatest variance in C/N ratios; (3) biochemically, stems were closer to roots than to leaves; hence the large portion of variation in C/N ratio in roots explained by variation in biochemical constituents in stems and leaves (R2 = 61.0%) and in stems only (R2 = 58.0%); and (4) statistical moments, other than mean values of biochemical constituents, significantly impacted C/N ratio estimates and the reliability of these estimates, both of which were positively correlated (r = 0.64, p < 0.001).