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

A base genética dos cultivares brasileiros de arroz, tanto de sequeiro como irrigado, tem sido considerada estreita, em vários estudos. Recomenda-se sua ampliação para diminuir os riscos da vulnerabilidade genética e elevar os patamares de produtividade. No presente trabalho, reuniram-se as genealogias dos cultivares de arroz recomendados para 1997/98 no Brasil, para os sistemas de cultivo de sequeiro e de sequeiro favorecido, e estimou-se a contribuição genética dos ancestrais. Essas informações fornecem importantes subsídios aos programas de melhoramento do arroz, para que os cruzamentos possam ser adequadamente planejados.Termos de indexação: arroz-de-sequeiro, genealogia, parentesco, base genética. ABSTRACT GENEALOGY OF BRAZILIAN UPLAND RICE CULTIVARSThe several studies have shown that the genetic base of upland and irrigated Brazilian rice cultivars is narrow. It is recommended, therefore, to amplify it, reducing genetic vulnerability and increasing yield. In the present work, genealogies of Brazilian upland rice cultivars recommended for 1997/98 for natural and supplementary -irrigation conditions (1) Recebido para publicação em 10 de setembro de 1998 e aceito em 30 de setembro de 1999.

Grain proteins from 58 Brazilian and nine Japanese upland rice cultivars (Oryza sativa L.) were electrophoretically separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Densitometric scanning of the electrophoretic profiles permitted the estimation of the relative concentration of 16 protein fractions, which were used as variables for the calculation of Fisher's canonical discriminating functions. Significant differences between mean values of protein fractions were useful in distinguishing Brazilian and Japanese cultivars, as well as improved and non-improved Brazilian rice cultivars in scattered plots. Electrophoretically detectable protein polymorphism in rice grain can indicate geographic origin as well as breeding improvement level of a cultivar. Improved cultivars were those released by plant breeding institutes.
Proteínas de grão de 58 genótipos de arroz brasileiro e nove japoneses foram separadas por meio de eletroforese (SDS-PAGE). A observação densitométrica dos perfis eletroforéticos permitiu avaliar as concentrações relativas de 16 frações protéicas que foram usadas como variáveis para a estimativa de funções discriminantes de Fisher. Diferenças significantes foram encontradas entre as frações protéicas dos grupos brasileiros e japoneses, assim como entre os genótipos melhorados e não melhorados. O polimorfismo protéico detectável eletroforetica-mente nos grãos de arroz pode indicar a origem geográfica e o nível de melhoramento dos cultivares

No abstract