Sorghum and Millets Commodity and Research Environments

Sorghum and millets are strategic commodities for worldwide food security, particularly in the harsh environments of the semi-arid tropics. This volume outlines the production and research environment of these crops in each major region, and seeks to provide a guide to the research required to achieve sustained improvements in production

A mechanism for inhibiting cross-fertilization in pigeonpea (Cajanus cajan (L.) Millsp.)

Natural out-crossing imposes considerable costs and inefficiencies in breeding, evaluation and commercialization of pigeonpea (Cajanus cajan (L.) Millsp.). This note reports identification of a modification of floral morphology which inhibits cross-fertilization. Floral morphology and possible mechanisms of action of this character are discussed

A procedure to assess the relative merit of classification strategies for grouping environments to assist selection in plant breeding regional evaluation trials

Classification methodology is widely used by plant breeders to group environments on the results of regional evaluation trials to assist in selection among genotypes. To be effective, this strategy must be integrated with the theory of indirect selection. Environments which group together should reflect commonality of genotypic discrimination and therefore give rise to similar selection among genotypes. Four strategies for classifying environments were compared. These were based on untransformed and three forms of transformed data (coded, standardised and rank). The comparison assessed how effectively the groups of environments formed by using each transformation maximised the opportunity for exploiting indirect selection between environments within the same group relative to environments in other groups. The objective in this study was to identify groups of international environments, used by CIMMYT in its international nursery program, which gave high indirect response to selection for grain yield in six Australian environments. Generally the four classification strategies identified subsets of international environments for which selection gave a greater indirect response than that for selection on average performance across all of the international environments (35% to 94% on average over all Australian environments). Environmental classifications based on the standardised and rank transformations were generally superior to those based on the untransformed and coded transformations (46% on average over all Australian environments). The magnitude of this advantage differed between the Australian environments but was substantial for the two environments which expressed the greatest opportunity for exploiting indirect selection. These results have obvious and large implications for the use of classification methodology to structure regional testing regimes for plant breeding programs

A New Source of Genetic Male Sterility in Pigeonpea

The identification of a new source of genetic male sterility in pigeonpea is reported. This source differs from that reported by Reddy et al, (1977), and oytological examination indicates that the abnormal anther development involves degeneration of the pollen mother cells at the young tetrad stage. This form of male sterility has been recovered in phenological classes ranging from 52 to 80 days to flower for December sowings at 27 S. The character is being maintained in ten phenological groups. This new source of genetic male sterility mil widen the genetic base for hybrid production in pigeonpea

Varietal Improvement of Pigeonpea for Smallholder Livestock Production Systems

Pegeonpea (Cajanus cajan) is widely grown in the tropics and subtropics as a soures of seed for human nutrition. I t i s most commonly used as jhai (dry s p l i t seed) i n vegetarian-based diets 3n the Indlan subcontinent. The seed contalns 20-25% protein. However, as we show i n t h i s 2aper pigeonpea seed also has considerable potential for animal feed and the p l a n t a s forage

Gene action in short-duration pigeonpeas

F1-F2 hybrids from a half diallel set of crosses involving 7 early Cajanus cajan lines were studied for yield and a number of yield-related traits. Parental performance was a good predictor of breeding value for most traits in the F1, but in the F2 a significant positive association between GCA effects and the parental performance was seen only for number of days to flowering. GCA variance predominated for all traits in the F1 and F2. The results suggested exploitation of the additive genetic variation in breeding for improvement of the cro

Photoperiodic response and accelerated generation turnover in chickpea

Rapid generation advancement enables the breeder to produce and test near homozygous lines in a shorter period of time. Chickpea (Cicer arietinum) is a quantitative long-day plant. Three experiments were conducted, two at ICRISAT Center Hyderabad and one at Bangalore, India, from December 1978 to August 1979 to assess potential of extended daylength to shorten the life cycle by early flower induction. The studies involved cultivars of different maturity groups. Twenty-four hour daylength treatment by using incandescent lights induced early flowering. All cultivars flowered simultaneously and took 32 to 35 days after sowing, in contrast to 32 to 74 days taken for 50% flowering under normal daylengths. Plants exposed to 24-h daylength had slightly increased plant height, more pods and larger seeds in one of the experiments. Physiologically mature pods could be harvested as early as 62 days after sowing from plants induced to flower early by 24-h treatment. Once flowering was induced, continuation of the extended daylength treatment had no effect on maturity. This technique will allow harvesting of more than one generation per year

A new gene for male sterility in pigeonpea (Cajanus cajan (L). Millsp.)

Several forms of female fertile and male sterile mutants in pigeonpea (Cajanus cajan (L). Millsp.) have been reported. A translucent anther type of male sterile characterised by non-separation of tetrads that is associated with a persistent tapetum is conditioned by a single recessive gene, ms1 (Reddy et al., 1977; Reddy et al., 1978). By contrast, a male sterile plant identified in breeding line B15B by Wallis et al. (1981) has shrivelled, arrowhead-shaped, non-dehiscent, brown-coloured anthers, and the pollen mother cells degenerate at the early tetrad stage (Dundas et al., 1981). This paper reports studies to determine the inheritance of the B15B male sterile character and its allelic relationship to the translucent anther type

Combined results on b-hadron production rates and decay properties

Combined results on b-hadron lifetimes, b-hadron production rates, B^0_d - \bar{B^0_d} and B^0_S - \bar{B^0_s} oscillations, the decay width difference between the mass eigenstates of the B^0_s - \bar{B^0_s} system, the average number of c and \bar{c} quarks in b-hadron decays, and searches for CP violation in the B^0_d - \bar{B-0_d} system are presented. They have been obtained from published and preliminary measurements available in Summer 2000 from the ALEPH, CDF, DELPHI, L3, OPAL and SLD Collaborations. These results have been used to determine the parameters of the CKM unitarity triangle