Accumulation of phytate in vegetable-type soybean genotypes harvested at four developmental stages

A total of 17 vegetable-type soybean (Glycine max [L.] Merr) genotypes were planted in four-row plots arranged in a randomized complete block design in 1988 and 1989 at Petersburg, Virginia. Each genotype was harvested at four developmental stages and evaluated for phytate content. Highly significant differences for phytate content were observed among the stages of harvest and genotypes, and there was an interaction between genotype x stage of harvest. The significant differences observed for phytate content among genotypes indicated that genetic variation exists among the tested genotypes for selection and improvement through hybridization. Among the genotypes, ‘Kingston’ and PI 423852 had the highest phytate content in most stages of harvest while PI 416771, ‘Emperor’, and PI 416982 had the lowest phytate values. A heritability estimate of 81 percent was observed for phytate content. This high heritability value indicates that selecting genotypes for lower phytate content would be effective. Significant correlations were observed for phytate content among genotypes harvested at R6, R7, R8, and overall. The magnitude of association of R6 with the overall phytate mean was especially high. These results illustrate that determining the phytate content of genotypes at the R6 growth stage would be a good predictor of the overall genotypic performance. Contribution of Virginia State University Agricultural Research Station. Journal Series No. 201. The use of any trade names and/or vendors does not imply approval to the exclusion of the other products or vendors that may also be suitable.     

Comparative seed yield performance of high-by-high and low-by-high crosses in flax *

Successful identification of a desirable segregant depends partly on the parents chosen to make the crosses. This experiment was conducted to compare performance and genetic variability for seed yield, yield components, agronomic traits and harvest index of lines derived from low- and high-yielding flax (Linum usitatissimum L.) crosses, and to identify important yield components for flax seed yield improvement. The lines chosen as high yielding parents for this experiment were‘Linott’and 'Summit; and the low yielding parents were‘Grant’and Ci2395. The high-yielding lines produced significantly more seeds per boll and had a higher harvest index than the low-yielding lines. Evaluation of 161 F_2:6 lines from four crosses among these lines showed that the greatest genetic variability, highest cross average, and highest F₆ line seed yield occurred in the low x high cross,‘Grant’x‘Linott’. All low X high crosses exhibited higher genetic variances for seed yield than the high x high crosses. The high x high cross 'Summit’x‘Linott’had low genetic variance for seed yield. Number of bolls per area was determined by linear regression, path coefficient analysis, and stepwise multiple regression analysis to be the most important component of seed yield. This study showed that hybridization of low and high-yielding flax lines may be useful to increase genetic variability and obtain high-yielding flax lines.     

Effects of temperature pre-treatment of transplants from in vitro produced potato plantlets on transplant growth and yield in the field

Summary In vitro produced potato plantlets, cvs Gloria and Spunta were planted in soil and exposed to day/night temperatures of 18/12 or 26/20°C for 14 days. They were then transplanted into the field in two experiments to assess after-effects of temperature on the performance of short-cycle crops. Accumulated intercepted radiation (AIR) was calculated from ground cover and incoming radiation, and dry matter production and fresh tuber yield were frequently recorded. Pre-treatment at 26/20°C caused higher leaf area at the end of the transplant production phase and resulted in a higher AIR at the end of the field phase than pre-treatment at 18/12°C. Higher AIR, however, was not associated with significantly higher yield. Initially, the proportion of dry matter partitioned to tubers was lower after 26/20°C, but this effect did not persist. High temperature pre-treatment may improve the performance of plantlets, especially of very early potato cultivars.     

Nutrient composition and anti-nutritional factors in selected vegetable soybean (Glycine Max [L.] Merr.)

The genetic variation in the nutrient composition and anti-nutritional factors of 17 vegetable soybean genotypes were determined and a wide variation in protein %, total phosphorus (TP_i) and available phosphorus (AP) was found among these genotypes. Variations in Ca, K, Fe, Mn, and Cu were also documented. Variation was also found for trypsin inhibitor (TI) activity and Phytate (PA) content. A highly significant and negative correlation (r=–0.533,P<0.01) was observed between TI and total protein. Strong positive correlation (r=0.90) was also found between TP_i and AP. Several genotypes (Sooty, Emperor, Wilson-5, PI 416771, PI 417322) showed good nutritional potential and can be used in the breeding program. High protein %, TP_i, and minerals are desirable qualities for vegetable-type soybeans that make it as food with high nutrient density. Studies on the nutritional evaluation of immature vegetable type soybean seeds at different reproductive stages are also underway.Agricultural Research Station Journal Article Series No. 172. The use of any trade name varieties, and/or vendors does not imply the exclusion of other products or vendors that may also be suitable.     

Estrus synchronization in sheep with synthetic progestagens

Sixteen female sheep of Degua breed were assigned to receive either the full dose of norgestomet ear implant and injectable solution containing norgestomet and estradiol valerate (n = 8) or half the dose (n = 8). The ear implants were removed in both groups on day 12. All ewes received an intramuscular administration of 500 IU PMSG at implant withdrawal. Synchronized ewes were individually hand mated twice at 48 and 60 hours after implant removal. One ewe in each group however refused mating on both occasions. Pregnancy diagnosis was conducted by bimanual external palpation 90 to 100 days post mating. The conception rates (3/7, 42.85%) and (5/7, 71.42%) were recorded in the two treatment groups, respectively. All eight ewes lambed between 145 to 153 days post mating. In group I ewes carried only singletons (prolificity rate 1.0) whereas in group II two ewes delivered twins, producing 7 lambs with prolificity rate of 1.4 (N.S). From this preliminary investigation it appears that the lower dose of norgestomet ear implants offers better option for estrus synchronization accompanied by higher fertility.