Maize - Maize

Figure 5. Genetic diversity for opaqueness and cobs traits in newly developed QPM lines

Low phytate:

• F3 progenies of five crosses (high tryptophan lines VQL1, VQL2, VQL17, VQL373 and SA12-1 with low phytate donor lpa2) were raised at ICAR-VPKAS Almora during kharif 2017.
• Selection for agronomic traits was carried out and selected individuals were selfed.
  
• F4 progenies of the crosses were raised at IIMR-WNC, Hyderabad during rabi 2017-18 for generation advancement.

                                                                                                                     Lane 2 – VQL1, Lane 3 – lpa2, F4 individuals in rest of the

Figure 6: Screening of VQL 1 × lpa2 progenies with CAPS marker (ZMGSPR1580)

                                                                                             Lane 2 – VQL1, Lane 3 – Lpa2, F4 individuals in rest of

 Figure 7: Screening of VQL 1 × lpa2 progenies with umc1066

• F5 progenies homozygous for lpa2 will be evaluated during kharif 2018 at ICAR-VPKAS Almora for agronomic performance
• Biochemical evaluation of self-seed of the selected progenies will be carried out for tryptophan and phytate content
• Test cross combinations among selected progenies of different crosses will be generated during rabi 2018-19 at IIMR-WNC, Hyderabad

 Further, three targeted F2 populations were generated and raised. F3 seeds were analyzed for low phytate content, and segregants with <9.0 mg/g of the phytate were selected (Table 2).

Table 2: Segreants with low phytate content

These low phytate progenies along with the already available low phytate inbreds would be crossed with the heterotic testers. 

Objective 2: Mapping of QTLs for high -Fe, -Zn, and storability of provitamin-A in maize kernels

Provitamin-A: Seven inbreds (VQL1-PV, V335-PV, HKI161-PV, HKI193-1-PV, CE-13, CE-25 and CE-477). possessing high proA (10.0-17.6 ppm) were stored for five months. Loss of proA during the storage was calculated which varied from 44-88%. Contrasting inbreds were crossed during rabi 2017-18 for generating F2:3 mapping populations. One desirable population would be selected for mapping of QTLs for retention of proA during storage.

Quality protein maize:

 A set of 350 diverse inbred lines panel have been constituted (Fig. 8). The seed of same were multiplied through hand pollination and has been evaluated for Fe and Zn at multiple location (total six).The sampling has been completed for Fe and Zn analysis for all environments. The analysis of samples for Fe & Zn is in progress, and so for completed for three environments. Based on available results, the sufficient genetic variation has been reported for Fe (8.1-63.5 ppm) and Zn (5.7-57.5 ppm) (Fig. 9). Depending upon the availability of fund during 2017-18, the DNA of 96 samples of panel was isolated, purified and quantified. The genotyping by sequencing (GBS) data has been generated for these samples. A preliminary study of population structure of association panel using SSR markers has reported six-sub-populations in the panel. The complete analysis of structure, kinship and association studies will be done once the Phenotyping and GBS for 350 samples will get completed

 Figure 8. Diversity in association panel

Figure 9. Phenotypic variation for Fe and Zn in association mapping panel

Objective 3: Designing and validation of gene-based marker(s) for lpa-1 and lpa-2 in maize:

Selected maize inbreds contrasting for phytate content were subjected to molecular analysis with the primers designed from lpa-1 gene sequence obtained from NCBI. The Gene specific primers were designed from the primer blast and the following are the details of the lpa-1 gene specific primers.

Lpa-2 gene (GRMZM2G456626) sequence was retrieved from MaizeGDB. Primers were designed from the reference sequence. Complete gene was amplified from available lpa-2, VQL1, V407 and VQL373. Overlapping primers were used to sequence complete gene from all these four genotypes. Only one (G/A) SNP was found in the coding region. As non-low phytate genotype VQL1 and low phytate genotype lpa-2 carry same allele of that SNP (G), it does not appear to be a functional polymorphism.

Objective 4: Studying the effects of QPM and/or provitamin A rich maize grains on nutritional status (lysine, tryptophan, provitamin-A) of eggs and meat

 The study was conducted to determine the effect feeding QPM based diets in Vanaraja birds. For the purpose, 175 numbers (day old chicks) were randomly divided into 5 dietary groups each having 7 replicates with 5 birds each. Five diets were formulated to contain normal yellow maize (NMY; Diet-1), Vivek Hyb 9 (Diet-2), QPM + pro A (Diet-3), QPM (Diet-4) and White Maize (Diet-5) (Table 4). The care was taken that all the diets were contained equal amount of essential amino acids, protein and energy. It has been observed that the improved body weight gain and feed efficiency was recorded among the groups fed diet with QPM + pro A compared to other diets during the 6 weeks of age (Table 5 and Fig 10). Though, there was numerical improvement in body weight gain and feed efficiency during the 9 week, it did not result in statistically significant difference between the dietary groups (Fig 11). At the end of the experiment, 7 birds from each treatment (each from a replicate) were sacrificed to study the slaughter variables. It has been recorded that the slaughter parameters did not vary among the various dietary groups. However, there was significant decrease in abdominal fat and increased breast muscle among the birds fed diet contained QPM (Diet-4) and QPM+proA (Diet-3) compared to other dietary groups.

Table 4. Ingredient and chemical composition of basal diet