No abstract

During 1995/96 and 1996/97, experiments (PI408251, Waseda, B6F4 (L-3 less), PI423909 and Tambagura).

Laboratory studies with Neomegalotomus parvus (Westwood) (Hemiptera: Alydidae) with one nymph per Petri dish in multiple‐choice tests indicated that seeds of pigeon pea [Cajanus cajan (L.) Mills.], lablab (Dolichos lablab L.), and soybean [Glycine max (L.) Merrill] were visited before seeds of common bean (Phaseolus vulgaris L.) and rice (Oryza sativa L.). The percentage of individuals engaging in dabbing/antennation resulting in probing, and percentage probing resulting in feeding, were higher on common bean (97%) and pigeon pea (87%) seeds than on lablab (55%), soybean (50%), or rice (5%) seeds. No significant differences were found in preference (number of flanges) among pigeon pea, common bean, and lablab, and preference (insects on foods) varied throughout the assessment period (5 d). In tests using 10 nymphs per dish, pigeon pea was the preferred food (number of flanges and insects on plants) throughout the period (5 d). In no‐choice tests, the average duration of a feeding session and the longest feeding session were greater on lablab and common bean than on pigeon pea, soybean, or rice seeds. The number of feeding sessions was greater on seeds of common bean, pigeon pea, and soybean than on those of lablab or rice. Laboratory tests with N. parvus adults indicated that pigeon pea seeds were located faster, followed by common bean, soybean, and rice. When pods were tested, dabbing/antennation time was shorter on pigeon pea than on soybean, and probing time was longer on soybean than on pigeon pea or common bean. On pigeon pea, 100% of the insects probed the host, while on common bean and soybean pods, and on rice panicles, these values dropped to 71.8%, 46.0%, and 10.5%, respectively. Adults showed similar feeding times on pigeon pea, common bean, and soybean pods, but did not feed on rice panicles. Electronmicroscopical analysis showed the presence of two apical lobes with 12 peg sensilla on the labial tip. Sensillum tips were stained with silver nitrate solution, indicating a permeability of the cuticle and, therefore, their function as taste receptors.

Long cooking time for soybean seeds hinders their regular 'in natura' use as a rich source of protein. The objective of this research was to study the genetic variability of cooking time in soybean and its correlation with seed weight and imbibition percent. Pure food-type soybean lines were assessed having been cultivated in a greenhouse (experiment 1) and pure lines derived from crosses between grain type and food type soybean cultivars cropped in the field (experiment 2). In experiment 1, wide variability was detected in all the traits and the cooking time varied from 26 minutes to 170 minutes. In experiment 2 the range of cooking time was less (63 to 124 minutes). The most pronounced correlations were between imbibition percent and cooking time (-0.41*) for experiment 1 and between seed weight before and after imbibition with cooking time (0.42 and 0.41*) for experiment 2. The results showed substantial genetic variability in soybean cooking time. This can be used to obtain cultivars for human consumption with important decreases in cooking time.

The purpose of this work was to compare the SPD (Single Pod Descent) and SPDS (Single Pod Descent with Selection) methods for segregating generation advancement in soybean breeding. Sixteen populations derived from crosses among Japanese and adapted Brazilian soybean were used. The traits, number of days to flowering (NDF) and to maturity (NDM), plant height at flowering (PHF) and at maturity (PHM), and individual plant yield (IPY) were assessed. The populations obtained by SPDS showed values close to the variation in the populations obtained by SPD. Regression through the origin showed that both methods were equivalent for NDM in the F