The dough characteristics of fifty popular Indian hexaploid wheat varieties were assessed by testing various rheological properties using a Brabender Farinograph and an Extensograph. These studies were aimed at evaluating the flour quality and functionality of the wheat dough. Based on the rheological dough properties of 50 Indian hexaploid wheat varieties it was recommended that 13 wheats could be useful for blending purposes, 31 varieties could be used for both bread and chapatti making, and the remaining 6 wheats were found suitable for biscuit making. The outcome of the experiments will be useful for plant breeders, millers and bakers.
Authors:T. Y. Reddy, V. R. Reddy, and V. Anbumozhi
Groundnut (Arachis hypogaea L.) is an important cash crop for tropical farmers. It is an annual legume and its seeds contain high amounts of edible oil (43-55%) and protein (25-28%). Even though it is fairly drought-tolerant, production fluctuates considerably as a result of rainfall variability. To develop a water stress response function in groundnut, research has been done to improve the performance under varying degrees of stress at various physiological stages of crop growth. This review summarizes recent information on the drought resistance characteristics of groundnut with a view to developing appropriate genetic enhancement strategies for water-limited environments. It is suggested that there are considerable gains to be made in increasing yield and stabilizing the yield in environments characterized by terminal drought stress and further exploiting drought escape strategy, by shortening crop duration. Many traits conferring dehydration avoidance and dehydration tolerance are available, but integrated traits, expressed at a high level of organization, are likely to be more useful in crop improvement programs. Possible genetic improvement strategies are outlined, ranging from empirical selection for yield in drought environments to a physiological-genetic approach. It is also suggested that in view of recent advances in understanding drought resistance mechanisms, the latter strategy is becoming more feasible. It is concluded that the use of this recently derived knowledge in a systematic manner could lead to significant gains in yield and yield stability in the world's groundnut production. Research is needed to develop transferable technologies to help farmers in arid and semi-arid regions. Increasing soil moisture storage by soil profile management and nutrient management for quick recovery from drought are some of the areas which need to be explored.
Attempts were made to produce tetraploid triticales by crossing 6x triticales with diploid rye. In F2, the chromosome number was reduced to between 15 and 23 except in three plants, where the chromosome number was 28, 32 and 38, respectively. An increased frequency of ring bivalents was observed in many F4 plants. In the progeny of the plant with 28 chromosomes, desired plants (four) with 2n = 28 chromosomes were obtained. Data on various agronomic characters were recorded on the progeny of these plants in F5. Reasonably good fertility was noticed in these tetraploid triticale forms.
The role of the different genome combinations in a polyploid on phenotypic stability was analysed in wheat and triticale. Twelve genotypes with four genome combinations (AABB, AABBDD, AABBRR and AABBDDRR) were raised in eight artificially created environments. The data on grains per spike, 100-grain weight and grain yield per plant were recorded and analysed following the models of Perkins and Jinks (1968) and Eberhart and Russell (1966). The results revealed that in polyploid species the genes for stability were not uniformly distributed in different genomes. It was therefore inferred that stability may largely depend on the gene combination rather than on the genome combination.
Authors:S. L. Patil, M. N. Sheelvanter, V. K. Lamani, and R. Reddy
A field experiment was conducted in Vertisols at Bijapur during 1994-96 to study the effect of tillage practices and integrated nutrient management on winter sorghum yield and soil nutrient availability. The increase in winter sorghum yield with deep tillage over medium and shallow tillage was 27 and 57% in 1994-95 as compared to 18 and 34% in 1995-96. Deep tillage resulted in 22 and 45% higher yield as compared to medium and shallow tillage in the pooled data. This was mainly due to conservation and increased availability of moisture and nutrients, i.e. N, P and K. The higher availability of nutrients in the topsoil (0-0.15 m) as compared to the subsoil (0.15-0.30 m) was due to the application of nutrients in the topsoil layer and the higher rate of mineralization. Among the organic materials applied, Leucaena loppings at 2.5 t ha-1 led to a significantly (9%) higher yield (1636 kg ha-1) over vermicompost (1500 kg ha-1) and was on par with farmyard manure (1572 kg ha-1) in the pooled data and during both years of the study. The higher percentage increase in grain yield with Leucaena application was due to the better moisture conservation and availability of major nutrients, i.e. N, P and K. Winter sorghum responded significantly to N application at 25 kg ha-1 in 1994-95, whereas in 1995-96 and in the pooled data the response varied up to 50 kg N ha-1. In the pooled data, the grain yield increased by 17 and 24% with the application of 25 and 50 kg N ha-1 compared with the control. The higher yields obtained with the application of nitrogen were due to the better availability of nutrients, especially N, as these soils are low in available N.
Authors:K. Gopal, E. Pradeepthi, V. Gopi, S. Khayum Ahammed, Y. Sreenivasulu, M. Reddy, V. Baranwal, and K. Purushotham
Huanglongbing (HLB), previously known as citrus greening disease (CGD) is one of the most destructive disease of citrus and responsible for decline of citrus orchards in Andhra Pradesh (A. P) and other citrus growing areas in the country. A preliminary survey on prevalence of HLB associated with citrus was carried out in three major sweet orange growing districts of A. P and the results revealed that a high incidence of 14.5% was recorded in Prakasam district followed by Kadapa (13.18%) and Nellore (12.59%). The DNA extracted from different plant parts of acidlime, i.e. bark, midrib, vein and lamina by CTAB and SS Tris-EDTA methods were subjected to PCR amplification. An amplification product of 1150 bp was observed in bark, midrib and vein. However, no amplification was observed in leaf lamina. Between CTAB and SS Tris-EDTA method, DNA from SS Tris-EDTA method yielded bright band compared to CTAB method. Detection of HLB in sweet orange was done from December 2004 to April 2005 at fortnight interval. It was observed that an excellent amplification product of 1150 bp was observed from December 2004 to February 2005. From March onwards a mild amplification of 1150 bp was observed in both the methods. So it can be concluded that winter season will be the suitable period for detection of the pathogen. Between these two methods of DNA extraction CTAB method was useful for detection of HLB in midrib and veins while SS Tris-EDTA method was useful for detection in bark of sweet orange.